I hope you are doing well

I was hoping for some advice regarding my 4-5 year old Horsfield tortoise, Kimchi. I adopted him in November 2023 and since then, he has generally been in good health, aside from summer last year when he became progressively more lethargic, and stopped eating. I took him to a specialist reptile vet (recommended on your site) and he was found to have quite a high burden of pin worms. They treated him for that x 2 (a standard course) but he didnt get any better, and when they tested him again found the worms hadn't cleared at all. At that point they did some blood tests and a mycoplasma swab - bloods were all normal but he was found to be mycoplasma positive. Luckily with another course of treatment for the worms they fully cleared and he was back to his old self and eating well, etc. They advised me that he likely has had Mycoplasma since a hatchling and that this probably wasn't a 'flare' as such - as he got totally better with the second course of deworming treatment, but explained that it was something that could flare up in the future - generally causing respiratory problems which need prolonged courses of antibiotics, and therefore should keep an eye out for any symptoms in the future and bring him back for early treatment if they do arise. They did say that he seems to be doing well despite having mycoplasma, however, and they wouldn't have picked it up had he not had the test because he initially wasn't clearing his worms. Apparently around 80% of Horsfield tortoises have mycoplasma.
From summer (after finishing his worming treatment) to December 2024 he has been completely fine, but since end of December/Jan time he has been sleeping a lot and not eating well. I havent hibernated him because the vet advised not to given he was poorly earlier in the year - and suggested we could do a shorter hibernation next year (shorter as he's at risk of a mycoplasma flare during hibernation). I took him back to the vet in January to check him over and they said he looked really healthy, with no worms or any symptoms/signs of concerns. They said that he wouldn't need to come back unless he developed respiratory symptoms (like a runny nose or breathing trouble, or his eyes were sticky) and that this was probably natural behaviour for the time of year. Since then he is eating a bit more - but not as much as usual and some days nothing at all, and doesn't actively wake up until I pick him and put him under the light. He will then tend to try and go back to sleep after not too long under his light/being awake. He is otherwise fine - no symptoms or signs of anything else amis, but hasn't been gaining weight given he isnt eating. I emailed the vet and asked if there was anything further I should do and they suggested I get reptoboost to put in the water when I soak him (which im doing every other day at the moment) but that he'd probably pick up as it started to get warmer.
Obviously it's the end of March now and I'm just worried he still seems so sleepy. Do you have any advice? Thank you very much in advance - and apologies for the long entry!
All the best
Emma