what is this white stuff on my crabs underside?

[_icosa_]

i posted on here a week or so ago asking about white stuff i saw in my crabs gonopores. i saw her climbing today and found it all along her underside on what appeared to be a clear-ish area of exoskeleton? apologies as i couldnt figure out how to upload photos.
the white stuff appears to be on the inside but this is the first time ive seen this much of it so i dont know now. i dont even know how long its been there since she doesnt let me pick her up and inspect her. i recieved her back in october or november and she had been very poorly cared for (you cant even call it care) so it could be from that long ago for all i know.
the area with the white bits looks like a bubble, its clear like the gonopores but is below them and is about the size of my fingernail. the only reason i saw it was because the opening to her shell is so wide and she was climbing upside down.
i belive shes getting ready to molt soon, could this have something to do with it? shes not showing signs of lethargy or feeling bad, shes very active and is eating and drinking normally. i have api pimafix if i need to treat her for fungal infections but i really dont want to use medicine unless theres no other option.
please someone tell me shes fine, or atleast that i can treat it. from what ive seen their underside should not have a giant clear bubble in it.

[curlysister]

It sounds like it could be a molt sac.
I wouldn't use any kind of treatment.

[wodesorel]

I can't find a better picture right now
viewtopic.php?f=123&t=92519

You see how the joints between the limbs match the gonorpore holes on this crab? In crabs that have a light or white colored underside, which is totally normal variation in their coloration, the jelly like joints will also be very pale, or even a little bluish or greyish.

They'll gain weight and fluid ahead of a molt, so the joints can be more pronounced than normal. After molting these areas can take on a vivid yellow hue as well for a few weeks.

[_icosa_]

apologies for the blurry image, this was the best i was able to get.
https://i.postimg.cc/nhXL46db/20230410-224629.jpg
you can see how its patchy, if it wasnt only in some areas i wouldnt be worried. both gonopores are only about half filled with the white stuff and i have no idea what it is. its in tiny patches everywhere thats clear, ive found no photos of anything like it anywhere