Sorry I don't use Win10, so can't test Microsoft edge. I will look to update mce. But busy at the moment.
Also having troubles with Edge for some of our users.
It looks like this is a known compatibility issue with TinyMCE that has been patched recently:
https://www.tinymce.com/docs/changelog/
Any chance to see an update soon?
And BTW, thank you for the great work!