PS2 random choppy framerate

When I first logged in after over a year, I was on Cape Terrigan and it was so choppy like 1 frame per second. When I warped back home everything ran smooth and when I went back later it was fine. Tested the last couple days in different zones and it worked fine. Last night I zoned out in Bastok Markets and when I logged back in it was back to 1fps ended up locking up after I tried to get further from the AH. Just wondering if this is a hardware issue or software issue?
I had read a few other threads of similar issues.
PS2 system with official hdd fresh install on brand new hdd.
Only one expansion installed (Rise of the Zilart). No issues with other games.
So far issues only in Cape Terrigan and Bastok Markets.
HDD check - no errors.
FFXI file check - no errors.
POL file check - no errors.

I'm not sure if this is anything but could this be related to the linkshell system?
After I logged in after the last issue that ended in a crash my linkshell had been un-equipped, but I'm sure it was equipped prior to the crash.

Another update - Bostaunieux Oubliette, bloodsuckers area. There was like 2 or 3 people with their trusts out and no matter what I did the framrate was terrible even if I wasn't by them. If I tried going to my storage the ps2 locked up. When I finally got back to the book and warped back to windurst frame rate was fine again. Might be an issue with the trust magic and ps2 ?

I'd look into upgrading to a different system, personally.

Not that there's absolutely 0 trouble shooting you could do, but there's just so many things that it could be that it's really not worth pursuing ya know? I mean, and maybe your specific system isn't this old, but the PS2 is over a decade old. HDD could be corrupted, RAM going bad, GPU/CPU issues, a multitude of electrical or mechanical issues, etc.

Thank you. It is hard to troubleshoot. I decided to try one thing before I moved on, a fresh hdd format then optimize hdd and install all the expansion data and update it all at once. This seems to have done the trick. Everything is much better now. framrate stutter is gone no weird crashes, everything runs much better, even logged out in different areas I had trouble with and it works great, for the ps2 version anyway. I'm guessing either the original data on the hdd was corrupt and or the update corrupted the data somehow as wipeing the original data and starting over worked. What's interesting is on the previous install I could never figure out how to release the Trust NPC, but now on the new install there is a release menu item that wasn't there before. Obviously something didn't update correctly, lol.