Cat spazzed out when I tried to make him poop in litter box

I have a 7yo male cat who sometimes poops outside the box. He is generally well behaved, very sweet, very tolerant. Loves cuddles. Is NOT temperamental/prone to hissing/scratching etc etc. Had one incident like 3 months ago where he randomly hissed at my partner and puffed his tail and meowed very loud and ran at them. This happened on and off for about 2 weeks, but the cat doc gave us gabapentin for him and we used it like 4x and he never did it again. I don’t think he was angry I think he was scared, but to this day I don’t know why. It’s never happened again.

Tonight I cleaned out the litter boxes (completely dumped them, sprayed them with disinfectant, and refilled). Within an hour I saw my cat scratching the ground and preparing to poop. I yelled his name (he knows his name) and he looked at me like “oh shit they caught me”. Then he moved to a different part of the room. About 3 min later he tried to poop on a different part of the floor. I picked him up and tried to place him on the litter box and he FREAKED OUT. Screamed/howled at the top of his lungs and hissed and made very erratic movement. Not sure if he was trying to lunge at me or run away but he got very upset, and I got scared. I’ve seen him almost poop on the ground before and moved him to the litter box and he’s always proceeded to poop in the box.

I don’t know what happened, but I allowed him to poop in the corner (I put a paper towel down under his butt once I saw him squatting) and gave him a gabapentin and some treats after. He seems fine now.

It made me very nervous and I’m wondering if anyone has had anything like this happen? My best guess is that maybe the smell of the disinfectant spray was still lingering & freaked him out? Idk. I’m hoping it’s not related to his weird behavioral change a couple months ago, but I guess we’ll have to see.

Thanks for any advice. Sorry this was so long 😭