I agree Scott, I thought upgrading my perfectly fine iPhone 7 Plus 256gb to the iPhone 8 Plus 256 gb would resolve my Notes issues, it didn't . Until Apple decides to fix this, we have to find short short term stop gaps to bridge us to the next iOS version that resolves this... your guess is as good as mine as to when that will be... Apple isn’t acknowledging that there is an iOS 11 problem, only offering suggestions to fix things on our end, when we all know it’s an Apple and iOS are 11 issue.
For those of us who are ardent Apple users with multiple Apple devices, laptops, desktops, Apple TV, tine capsules and OS’s, and who are walled into the Apple realm and can’t easily move off to another platform... we have no choice but to wait. I’ve seen this neglect from companies before... Motorola, Nokia, Blackberry, Sony... all popular platforms that neglected thier fans and user base and we all know what happened to them, this paragraph was for Apple... we know they are listening and reading this... Our loyalty only goes so far...
Here are a few observations and minor stop gaps, when Notes freezes, often it’s in some type of “wait state”, that is it sometimes takes up to a minute or so and the Note will unfreeze, not a great solution, but sometimes it beats restarting Notes.
When the Note freezes, instead of starting off with the same note, go back to the main Notes screen, restart there, and then go back to your Note, that often gives you some working time (not much) before Notes starts crashing and freezing again. Often when Notes crashes and restarts on its own my screen flashes a bunch of static, then restarts... then reverts to the main Notes screen. Notes will work for a bit and then crashes again.
I added the Evernote app right next to the Apple Notes on my iPhone, cut and pasted my critical Notes, when Apple Notes starts crashing again, I go straight to Evernote and keep working. Not a great solution, but keeps me productive while Apple is hopefully working on this issue(s). I don't work for Apple, so who know when that could be?