diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 417bfd25e..7ec1394bd 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -27,7 +27,7 @@ on:
       #- edited
       #- closed
       #- reopened
-      #- synchronize
+      - synchronize
       #- converted_to_draft
       #- ready_for_review
       #- locked
@@ -61,7 +61,7 @@ jobs:
       - name: Get current year-month
         id: date
         run: echo "::set-output name=date::$(date +'%Y-%m')"
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
 
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v2
@@ -69,13 +69,14 @@ jobs:
           python-version: ${{ matrix.python-version }}
 
       - name: Cache test_env
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         with:
           path: ~/test_env
           # Look to see if there is a cache hit for the corresponding requirements files
           # cache will be reset on changes to any requirements or every month
           key: ${{ runner.os }}-venv-${{ hashFiles('**/requirements.txt') }}-${{ hashFiles('**/requirements-tests.txt') }}
-            -${{ hashFiles('**/requirements-extras.txt') }}-${{ hashFiles('setup.py') }} -${{ steps.date.outputs.date }}
+            -${{ hashFiles('**/requirements-extras.txt') }}-${{ hashFiles('**/CI.yml') }}-${{ hashFiles('setup.py') }}
+            -${{ steps.date.outputs.date }}
 
       - name: Install dependencies
         run: |
@@ -121,13 +122,13 @@ jobs:
         id: date
         run: echo "::set-output name=date::$(date +'%Y-%m')"
 
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
 
       - name: Cache conda
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         with:
           path: ~/conda_pkgs_dir
-          key: ${{ runner.os }}-conda-${{hashFiles('requirements/environment.yml') }}-${{ steps.date.outputs.date }}
+          key: ${{ runner.os }}-conda-${{hashFiles('requirements/environment.yml') }}-${{ hashFiles('**/CI.yml') }}-${{ steps.date.outputs.date }}
 
       - uses: conda-incubator/setup-miniconda@v2
         with:
@@ -183,19 +184,19 @@ jobs:
         id: date
         run: echo "::set-output name=date::$(date +'%Y-%m')"
 
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v2
         with:
           python-version: ${{ matrix.python-version }}
 
       - name: Cache pip
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         with:
           path: ${{ matrix.path }}
           # Look to see if there is a cache hit for the corresponding requirements files
           key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}-${{ hashFiles('**/requirements-tests.txt') }}
-            -${{ hashFiles('**/requirements-extras.txt') }}-${{ hashFiles('setup.py') }} -${{ steps.date.outputs.date }}
+            -${{ hashFiles('**/requirements-extras.txt') }}-${{ hashFiles('setup.py') }} -${{ hashFiles('**/CI.yml') }}-${{ steps.date.outputs.date }}
 
       - name: Install dependencies
         run: |
@@ -233,7 +234,7 @@ jobs:
       - name: Get current year-month
         id: date
         run: echo "::set-output name=date::$(date +'%Y-%m')"
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
 
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v2
@@ -241,13 +242,13 @@ jobs:
           python-version: ${{ matrix.python-version }}
 
       - name: Cache test_env
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         with:
           path: ~/.cache/pip
           # Look to see if there is a cache hit for the corresponding requirements files
           # cache will be reset on changes to any requirements or every month
           key: ${{ runner.os }}-venv-${{ hashFiles('**/requirements.txt') }}-${{ hashFiles('**/requirements-tests.txt') }}
-            -${{ hashFiles('**/requirements-extras.txt') }}-${{ hashFiles('setup.py') }} -${{ steps.date.outputs.date }}
+            -${{ hashFiles('**/requirements-extras.txt') }}-${{ hashFiles('setup.py') }} -${{ hashFiles('**/CI.yml') }}-${{ steps.date.outputs.date }}
 
       - name: Setup enviroment
         run: |
@@ -282,13 +283,13 @@ jobs:
       fail-fast: false
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
 
       - name: Cache pip
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         with:
           path: ~/.cache/pip
-          key: ${{ runner.os }}-pip-${{hashFiles('requirements/environment-tests.yml') }}-${{ steps.date.outputs.date }}
+          key: ${{ runner.os }}-pip-${{hashFiles('requirements/environment-tests.yml') }}-${{ hashFiles('**/CI.yml') }}-${{ steps.date.outputs.date }}
 
       - name: Add conda to system path
         run: |
@@ -296,6 +297,7 @@ jobs:
           echo $CONDA/bin >> $GITHUB_PATH
       - name: Install dependencies
         run: |
+          conda config --add channels conda-forge # bugfix with scipy==1.8.1: libstdcxx-ng 12.1.0 required
           conda update conda
           conda env update --file requirements/environment-tests.yml --name base
           activate base
@@ -330,7 +332,7 @@ jobs:
         id: date
         run: echo "::set-output name=date::$(date +'%Y-%m')"
 
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
 
       - name: Add conda to system path
         run: |
@@ -338,11 +340,12 @@ jobs:
           echo $CONDA/bin >> $GITHUB_PATH
 
       - name: Cache pip
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         with:
           path: ~/.cache/pip
           # Look to see if there is a cache hit for the corresponding requirements files
-          key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements-docs.txt') }}-${{ hashFiles('**/requirements-tutorials.txt') }}-${{ hashFiles('**/environment-docs.yml') }}-${{ steps.date.outputs.date }}
+          key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements-docs.txt') }}-${{ hashFiles('**/requirements-tutorials.txt') }}-${{ hashFiles('**/environment-docs.yml') }}
+           -${{ hashFiles('**/CI.yml') }}-${{ steps.date.outputs.date }}
 
       - name: Install dependencies
         run: |
@@ -350,6 +353,7 @@ jobs:
           python -m pip install --upgrade pip
           pip install -r requirements/requirements-docs.txt
           pip install -r requirements/requirements-tutorials.txt
+          conda config --add channels conda-forge # bugfix with scipy==1.8.1: libstdcxx-ng 12.1.0 required
           conda update conda
           conda env update --file requirements/environment-docs.yml --name base
           conda install -c conda-forge openmpi