Hi, I don't know how to start this off so i'll give a quick backstory. I got my second snake, Aries, around 5 months ago. My first snake i only got a month before her so i'm new to snake keeping but i do understand that bp's are notorious for going on hunger strikes.
Aries is 2.5 years old and was only 427 grams when i got her. I almost didn't believe the breeder about her age because of her weight but judging by her length and comparing her to my other snake who is a year younger than she is, i think she probably is the age they told me. The breeder told me she was a picky eater often refusing to eat and would only eat smaller sized rats since she wouldn't even bother with larger ones, which would explain her weight.
I gave her a month to settle in, only checking in on her to offer her a rat or top up her water and spray her tub, and she settled in well.

Since i got her, she was eating on and off every week, so she'd eat one week, not eat the next, and so on. She did that or a month and a half and then started eating consistantly for 9 weeks, only skipping two meals. She put on 100 grams and was steadily gaining weight at the same rate as my other snake (who is now 750 grams so she's fallen behind so much). When i came to feed her a week later, she struck the rat and decided not to eat it. No big deal. Next week she did the same thing. Then the week after, and now she hasn't eaten for 8 weeks. I understand some snakes go for months and months without food but her weight is what is worrying me along with some other strange behaviours.

She always without fail strikes the rat that i offer to her. She coils it, and constricts when i wiggle it around but she never eats it. I've tried lifting her cave and feeding her inside the cave, having her come out of the cave to take the rat, covering her tub, keeping her tub uncovered. Feeding her before my other snake, feeding her after my other snake. Giving her white rats, coloured rats, rats sizing from 21 grams to 36 grams (which i know isn't huge but while she was eating, those were the only sized rats she would take, the biggest she'd eaten was 40grams). I've tried not wiggling the rat after she strikes it, leaving it with her for 30 mins/two hours/overnight. I've offered her room temp rats, warm rats, hot rats. She always shows interest once she smells the rat, she comes out of her cave and flicks her tongue around looking at the rat and strikes consistantly, but won't eat. I've started to offer her food less often, every 10 days but i'm thinking about making it two weeks.

For the past two weeks, she's been coming out of her cave and wandering around every single night. Nothing about her husbandry has changed. She's in a 2 x 1.5 ft tub (i was planning on upgrading her until she stopped eating and now i don't know what to do), heat mats on both the cool (26-27C) and hot (32-33C) sides. Two identical caves over each side, lots of fake leaves for cover, a large water dish, and reptile prime substrate. I checked her temps today before posting and i checked them directly with a temp gun, along with digital probe thermometers. Temps are monitored using habistat thermostats on both mats. And her humidity is usually in the high 50's to low 60's range unless she's shedding so i'll raise it higher. I've recently covered up her tub so she can't see out of it in case that was causing her stress, i don't know if that was the right decision?

Also she is ALWAYS in her cool side cave. I rarely ever see her in the hot side cave, but her temps are where they're meant to be so it surely couldn't be because it's too hot for her?

I have no idea why she's suddenly stopped eating after making such good progress, why she always strikes the rats but never eats them, why she's now coming out of her cave every night for seemingly no reason, why she's only using her cool side cave, so i was hoping someone could offer some help? Also her weight worries me. I've been monitoring her weight and she's lost almost 30 grams since she stopped eating (she's now 491g).

I honestly don't know what to do. Everything went perfectly with my other snake, he was eating live rats when i got him and took a F/T rat the first time i fed him, he's only ever missed 1 meal in 5 months, and hasn't given me any issues at all.

I just want to make sure Aries is okay and that she's not going to die on me, i'd be devastated if anything happened to her so any help is muchly appreciated. I'm trying to resist the urge to rush her to my exotic vet since i know they can't really do much for a snake that isn't eating, but it's the other strange behaviours and her initial weight that has me worried the most.