That is a complicated situation - wow. All right, it seems that his immune system being down along with the changes caused him enough stress to get UTI. On top of that, your friend's routine has changed so...everything is upside down for him right now and it's causing him distress.
My guess is he's definitely bored. Even though you went out of your way (really, out of your way) to entertain him and provide him with more, a highly social cat, a young one at that, being confined to one room...it's tough. But, that's the way it has to be. Let's look at the straw that broke the camels back.
Your friend - how are they together? Do they just tolerate each other or do they get along well normally? What is their interaction like and is your friend a cat person? It almost...looks like he's suffering from FOMO - fear of missing out. Suddenly, there is a lot more action in the house, action he'd normally get to be a part of. I can see how that would be frustrating, as such. Otoh, if your friend is making 'different' noises (maybe due to the surgery, maybe due to being home during the day instead of at night when you're more likely to sit down on the couch?), it could be that he cannot really figure out what is going on out there.
Either way, I think the key might be to have your friend go into the room with Cricket, if their immune system is up to it, and have some one-on-one playtime with him as well, so he gets that this is the new routine now.
See if you can also give Cricket some more routine again. His world has been literally turned upside down and cats thrive on routine. Make use of the Play-Food-Groom-Sleep cycle they go through and make him go through that repeatedly if you can a day. Play with him, feed him, watch him groom and settle in for a nap. Especially handy if he cries at night, but also to just shut him up during the day. Do this at the same time every day - establish that expectation and make his environment predictable again in every way. Yes, it has changed, but no, it's nothing to worry about.
And have your friend be a part of this, so he knows that this is normal - this is the way things are now and there is nothing to worry about
And as always - do not reward that meowing, so try to go in when he has a moment where he *doesnt* meow, to avoid association with meowing and your presence, coz otherwise it will only get worse!
Amar- thanks so much for your insights & suggestions. Pardon the delay in my response, been busy/mentally drained the past week & wanted to reply when I could give some coherent feedback.
I think you're right on the money about Cricket suffering from FOMO (/fear of missing out), as far as the constant crying everytime he hears my friend existing at all in her own apartment, since she's usually gone.
She & Cricket get on very well (it's probably impossible for him to dislike everyone, he's such a social/lovey guy). A day or so after your post, my friend was increasing her post-op activity, which included supervised careful walks up the stairs, so she'd once a day get to the top of the stairs, crack the bedroom door open/say hi to the crickets/give a [gloved] pat, then go back downstairs. Shortly thereafter, we'd hear Cricket beating up his favorite jingle bell ball, happily.
My disinfecting time in the room has gotten more regular (a morning routine), where I first feed Cricket, then he lays all over me for about a half hour (we watch an episode of
The Simpsons together), & he'll curl up on my lap, knead on me, nosekiss me, & groom/possibly fall asleep on my lap, at which point I sneak his topical medication onto his ears/neck/tail. When the episode's over, I open the window & sit him in front of it to watch birds while I vacuum & disinfect the room, which takes about 30-45 min. He doesn't ever get stressed over the noise, at least. Then I pat him 'bye, & go back downstairs.
The past few weeks, he'd be extra clingy when I was done cleaning/leaving. Chasing me to the door, & howling, trying to grab at me from under the door while I'd be removing the protective clothing in the hall (so as not to carry spores through the apt). However, it seems the consistency w/timing has calmed him down significantly in a surprisingly short time. No more panicky grasping under the door the second I leave. He just lays on the desk at the window, in the sun, 90% of the time.
Before that relaxed pattern emerged, he managed to dart out around me one day, & ran halfway down the stairs, but stopped dead in his tracks when my friend met him at the bottom, to stop him from contaminating the place. As soon as he saw her, he just stopped, rubbed his face on the stair rail, & ran back up the steps to me/tried to rub me, then ran back in the bedroom. I assume that was a manifestation of the FOMO, haha. Kinda translated the situation as, "I WILL FIND OUT WHAT'S GOING ON DAMMIT! FREEEEEEEDOM!!!!! ----Oh hai other lady! I likes you. Did u know I own these stairs?" *mark* [now somewhat satisfied about the strange noise sources] " kthxbai! --- MUM I LOVES U NO CAN HAZ A MAD" *runs back into room/rolls around, trying to look cute*
It really amazes me how sensitive cats can be to changes in their routine. It's been hard for me to think clearly some of the time, lately, worrying about/assisting my friend & also monitoring Cricket's UTI issue (he was in so much pain, not walking right... he's ok now, has a followup appt tomorrow), it was hard for me to realize on some level that schedule changes/random noises could create that much inner turmoil for him. It seems pretty obvious in hindsight.
Also (regarding positive association to meowing) - because he was on a few different short-term meds (antibiotic, muscle relaxer, & a painkiller for the UTI), his feeding times were a bit off-schedule. Some of those meds required food, & he also had dropped weight/needed to put it back on, so he was getting *extra* feeding times, which probably created a reward system in his mind for his constant yowling. He's off those meds, now, & I just increased the amounts of food I give him during his 2 normal feeding times. I appreciate the reminder about accidentally creating a reward system with food. I've been so scattered, lately.
This has gotten pretty long, & wheels are turning everywhichway in my head still to go catch up on crap I need to do, so I'll end this here, for now, & keep you posted w/his progress. So far, it seems like his anxiety is scaling back, as he adjusts to the new sounds downstairs, & gets some of his old schedule back.
Thanks again, Amar <3
(and the crickets thanks you, too)