Yeah, this is part of of my experience with hypermobility.

Based on what you're describing, that would indicate hypermobility to me. I would also look into Ehlers-Danlos testing.

Absolutely, I've dislocated things just sitting there as well. My knee caps will roll to the outside of my leg while my shin and calf snap outwards to the side as well and it is very hard to get back into place and I can simply be standing there or in the middle of walking.

Oh and my personal experience in trying to get treatment was "we can't do anything about it, just build up your muscles and you'll be fine" but I know it's not like that for everyone.

I had a similar experience when I was younger. I’ve always had hypermobility and can bend my body in unnatural ways and pop my joints on command. Generally I just ignore it and it’s not a problem. However, when I was in grade school one year my knees started to pop out randomly on their own and I would be in so much pain I couldn’t move until I forced them to pop back in properly. The doctors figured out I’d increased my level of physical activity within the past year and that’s what had started it. Essentially because of my hypermobility, when my leg muscles got tired from exercising, instead of cramping up or feeling sore they’d just switch over to different (wrong) muscles. They were concerned I’d build up the wrong muscles too much and I’d damage my legs, so I went to physical therapy for a year. I built up my muscle tone in the correct muscles, which stopped my body from being able to switch to the wrong ones, and it hasn’t been a problem since. If it’s happening in your ankles pay extra attention to how your feet are position when you walk to see if you’re angling your feet in (pigeon toed) or out (duck footed) instead of walking straight. In any case, if you’re experiencing involuntary joint popping and pain with your hypermobility you should probably see a doctor.

Oh heck yeah, if you, like I do, sit criss-crossed- applesauce you likely are pushing your ankle out of the place it belongs without realizing! It’s a big big thing that happens to me! Everything you’ve described is something that has happened to me, I have an official hEDS diagnosis. Which is a pain in the ass to get, but it might be helpful for you? Hyper mobility seems like a distinct possibility for you, based on what you’ve discribed!

Literally happens all the time, definitely look into EDS and other HSDs, at first it I wasn't sure it was worth it but my diagnosis has really saved me a lot of time with any of my new problems. Check out the EDS Society online or I also like this lady name Hypermobilty MD on instagram. They have tons of info and people who deal with the same thing!