A Flow which worked fine for weeks now continuiously in errors.
When trying to fix this problem I found out I can't even save the Flow properly anymore.
Sometimes the Flow can be saved, sometimes these errors are shown:
The power flow's logic app flow template was invalid. The 'type' property of template trigger 'manual' at line '1' and column '39305' has the value 'Manual' which is deprecated in schema version '2016-04-01-preview' and onwards.
Definition contains invalid parameters.
Furthermore I found this text in a 'Update File properties' part:

I haven't added this text.
Please see this video for a demonstration:
https://youtu.be/bfi-rGNA3wY
Note: we didn't change anything on the Flow or SharePoint library to which it is connected.
I've tried to export and import the workflow bu the problem persists.
Also tried to change the 'manual' property which the first error refers and then import the Flow, but Flow won't import the Flow.
How can this Flow be fixed again?