I had to giggle about cleaning ketchup off your private key napkin, make sure you don't confuse that napkin with all the other napkins XD
Good thing you were awake enough to note something wasn't quite right O_O and also it was fortunate you had people that you could reach out to for help, I feel like where people really get stuck/scammed is if they don't have that x_x
I kind of vaguely remember something similar happening a bit back but I think my problem was to do with Hive Keychain and it was somewhat mitigated by using peaklock for a bit instead (I've been back to Hive Keychain with no dramas). I will double check to see if I get the same rewards claim problem as you (it throws an error every so often which looks kind of vaguely similar but I haven't actually looked at it properly as it seems that it does actually do what it's supposed to be doing despite crying about it.
I will remember, I have mayonnaise on the one with my bitcoin address.
Account security is something you get much more serious about after a close call like this. Being able to reset password like on other services had lulled me into a false sense of security. I was lucky that I could contact people through HiveChat.
I will be updating this post soon because I have resolved my error issues. Turns out it was either Brave browser of the Keychain plugin there. I tried using Firefox and everything is OK there.