Same problem with notes turning to “view only. iOS on iPad Pro, Evernote 10.12.
Evernote 10 has not been a joy. Slow, buggy, trying to be fancy.
I still run Legacy in parallel for things like editing encrypted text -just nuts to have to do such workarounds. Has all the trappings of developers who are too close to the product and, even though they probably use it, have lost most claims to understanding how real (I.e. less-knowledgeable) people use it. Take a lesson from CraigsList: keep it simple and make it work!