diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOpAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOpAnalyzer.php
index 79fda5cbdec..615a2f7c307 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOpAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOpAnalyzer.php
@@ -777,7 +777,7 @@ function (\Psalm\Internal\Clause $c) use ($mixed_var_ids) {
             if ($stmt_left_type = $statements_analyzer->node_data->getType($stmt->left)) {
                 $if_return_type_reconciled = AssertionReconciler::reconcile(
                     '!null',
-                    $stmt_left_type,
+                    clone $stmt_left_type,
                     '',
                     $statements_analyzer,
                     $context->inside_loop,
@@ -786,7 +786,7 @@ function (\Psalm\Internal\Clause $c) use ($mixed_var_ids) {
                     $statements_analyzer->getSuppressedIssues()
                 );
 
-                $lhs_type = $if_return_type_reconciled;
+                $lhs_type = clone $if_return_type_reconciled;
             }
 
             $stmt_right_type = null;
diff --git a/src/Psalm/Internal/Type/NegatedAssertionReconciler.php b/src/Psalm/Internal/Type/NegatedAssertionReconciler.php
index 29d695b48a3..df36f72cbea 100644
--- a/src/Psalm/Internal/Type/NegatedAssertionReconciler.php
+++ b/src/Psalm/Internal/Type/NegatedAssertionReconciler.php
@@ -9,6 +9,7 @@
 use Psalm\Internal\Analyzer\StatementsAnalyzer;
 use Psalm\Internal\Analyzer\TraitAnalyzer;
 use Psalm\Internal\Analyzer\TypeAnalyzer;
+use Psalm\Issue\DocblockTypeContradiction;
 use Psalm\Issue\ParadoxicalCondition;
 use Psalm\Issue\RedundantCondition;
 use Psalm\Issue\TypeDoesNotContainType;
@@ -104,14 +105,28 @@ public static function reconcile(
                             $failed_reconciliation = 2;
 
                             if ($code_location) {
-                                if (IssueBuffer::accepts(
-                                    new TypeDoesNotContainType(
-                                        'Cannot resolve types for ' . $key . ' and !isset assertion',
-                                        $code_location
-                                    ),
-                                    $suppressed_issues
-                                )) {
-                                    // fall through
+                                if ($existing_var_type->from_docblock) {
+                                    if (IssueBuffer::accepts(
+                                        new DocblockTypeContradiction(
+                                            'Cannot resolve types for ' . $key . ' with docblock-defined type '
+                                                . $existing_var_type . ' and !isset assertion',
+                                            $code_location
+                                        ),
+                                        $suppressed_issues
+                                    )) {
+                                        // fall through
+                                    }
+                                } else {
+                                    if (IssueBuffer::accepts(
+                                        new TypeDoesNotContainType(
+                                            'Cannot resolve types for ' . $key . ' with type '
+                                                . $existing_var_type . ' and !isset assertion',
+                                            $code_location
+                                        ),
+                                        $suppressed_issues
+                                    )) {
+
+                                    }
                                 }
                             }
 
diff --git a/tests/TypeReconciliation/IssetTest.php b/tests/TypeReconciliation/IssetTest.php
index e1d26ce8a8f..3e920132bad 100644
--- a/tests/TypeReconciliation/IssetTest.php
+++ b/tests/TypeReconciliation/IssetTest.php
@@ -742,6 +742,30 @@ function foo(?A $a) : string {
                         return "bar";
                     }',
             ],
+            'issetOnMethodCallInsideFunctionCall' => [
+                '<?php
+                    class C {
+                        public function foo() : ?string {
+                            return null;
+                        }
+                    }
+
+                    function foo(C $c) : void {
+                        strlen($c->foo() ?? "");
+                    }'
+            ],
+            'issetOnMethodCallInsideMethodCall' => [
+                '<?php
+                    class C {
+                        public function foo() : ?string {
+                            return null;
+                        }
+                    }
+
+                    function foo(C $c) : void {
+                        new DateTime($c->foo() ?? "");
+                    }'
+            ],
         ];
     }