With either TWRP and OrangeFox I can see files in sdcard folder with long character filenames, could it be possible that something went wrong with Android 10's per-file encryption when I flashed this ROM? Anyway I decrypt the files for backup? The OrangeFox does not prompt for decryption pin.
Something went wrong with your encryption/decryption. Orangefox/TWRP should ask for your pin when you start them. Or go rummage around in the settings to see if you can find a decrypt function.
If you don't mind resetting your phone from scratch, the easiest solution would be to do a full format in TWRP (format data, where you have to type yes to do it).
And then flash whatever rom you want (including this one). You will have to start from zero, all data on your phone will be gone, but everything is on the cloud anyway these days. Takes max 1h to redownload all your apps, and google will do it all for you anyway.
It should work flawlessly after that.
(there might be non-format solutions, but I find the format solution easy and hassle free. If you don't want to lose all offline data, wait for someone more knowledgeable to help you)
I did the flashing with TWRP, changing to Orangefox after noticing TWRP not prompting for decryption pin. Yes, it is true I am reluctant to setup everything again so I hope someone able to help. Digged through Orangefox found no settings regarding to decryption.