OK that's two different problems - video lockups like you were having and IVS working randomly are two very different things.
If it's autotracking working randomly then yes the newer firmwares definitely seem to get confused at times with it seeming to have a dodgy alhorithm with autotracking guessing where something is going and panning right past objects and getting into a tailspin.
It definitely seems to work better in some environments than others!
I've changed my cam to 60fps to see if it starts to show the lockups you were seeing Kamakzie.
What is your ambient temperature where you are to be getting 50c readings? The reason I'd asked for the temperature was to see if we could confirm the fans are working in case that causes lockups.
My 1A225 has gone up to 90c twice now and B&W mode but that is a firmware bug as a quick power cut and things are back to normal although I've never seen that on the 59225
That's a good point though actually - sometimes when these things get confused a full power cut to the camera is a better place to start than just a soft reboot and on these PTZ cameras I have a daily reboot set otherwise things do sometimes go very wrong too so maybe think about that.
I've got some older firmwares dating back to 2017 you're more than welcome to try from the time I've had the PTZ - you may not be able to go all the way backwards as sometimes they stop you rolling too far back but they're all here.
MEGA
Some of those are compressed rar or zip files so would need uncompressing before sending to the camera (not wanting to teach either of you to suck eggs but I don't know who else will download those and try and load them on the cameras)