Router crashes on pages with more than 9 root elements

[themoenen]

Version

3.1.2

Reproduction link

https://codesandbox.io/s/happy-euclid-610gx

Steps to reproduce

Switch multiple times between any page and page C. Error happens on the second time and will break page rendering after 1st element.

What is expected?

No error

What is actually happening?

"Unhandled error during execution of scheduler flush" --> "Cannot read property 'cloneNode' of null"

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Problem is related to [email protected] — downgrading to [email protected] solves the problem.
Problem can also be worked around by wrapping page content in a div.

Smells the same as #4023, #4031 and #4030

[posva]

Thanks, I added a repro without the router at #4023