Hi @martin3418, I’m so so glad to hear you installed /e/, great job! I haven’t had a single issue since installing /e/ 2 months ago. OTA updates have been completely fine.
If you haven’t already tried, I recommend downloading F-droid and Aurora Store. I’ve experienced non-downloads from the /e/ App store, which I have rectified using these stores instead. Aurora store is basically the google play store without a google account; if you’re using /e/ I assume you’ve heard of F-droid. I’ve just tried, and both ProtonVPN and Brave work for me fine from Aurora store, but not from the /e/ app store.
I don’t share your experience with the Files app, and I can’t suggest what to do, but you could report it on github, or just make a seperate post about this issue, and some one more knowledgeable than me can comment on it!
Finally : I am also a total newbie, but from all the research I had to put in to installing /e/, I remember coming across this post about re-locking the bootloader, which I hope helps with answering your question.
Thanks for getting in touch with me have a lovely night! 