I can't get a picture, the best camera I have is on my phone and it's not going to do the job. Here's maybe a better description...
posture: head and tip of tail down, middle of body hunched up
big gap between head/body part and abdomen/tail part...between the body and the first tail segment.
you can see the bright yellow of the saddle very clearly through the gap, looks like it's bulging up and creating the gap, pushing the two segments apart.
Not a lot of movement, kind of slumped over, still eating occasionally.
If that doesn't paint any better of a picture, no worries. The molting difficulty theory makes sense based on the look of things. I'll keep watching and watch for dead shrimp and add the dolomite if necessary. Thanks!