Yes I definitely do want to downgrade the CFW, as I have a complete backup images of my old PSP1001 with all my preferred apps and games and stuff, complete with Game Categories plugin, which apparently CFW 6.4 doesn’t like.
CFW 6.4 also doesn’t seem to like half my other mods either, like modding Descent 1.4 to work on anything above OFW 1.5, while I had that working on 5.00 M33-6.
I have so many custom mods on my old imaged backups it ain’t funny, but how, if even possible, can I reflash the NAND and downgrade the CFW to my old backup image?
With CFW 6.4, the PSP won’t even boot up with my memory stick, I have to shut it off, pull the stick out, then boot it up without the stick, then put the stick back in.
Anytime I exit an app or game, the PSP locks up and I gotta power off and reboot, as stated above.
The Game Categories plugin does not work.
Absolutely none of my homebrew meant for OFW 1.5 work at all.
None of this is acceptable, and none of this would be any issue if I went back to my version of CFW 5.00 M33-6.
I’m sorry, I have no experience with any of the problems you mention.