Our silver tabby loves the litter box, when we clean it out and refill
it, she will either:

Go in and lie down. Nothing else. Just lie there.

OR

Wait close by for the other two to come and use it (it's always a race
to see who gets to be the first to soil the new litter) and attack them
while their doing their business.

*** I'd say something is definitely not right with her. It could be
behavioral, or physical. Cats are almost always very clean by nature ( or at
least most cats (that are) in good health and happy), so her behavior is
clashing with that fact. I'd have a verrry hard time wanting to cuddle with
her or kiss her if she constantly plays or rolls around in her litter box.
That would drive me bats.

You can call a good, reputable, vet's office in your area. Ask if you can
ask a question to a Tech, and if so, then mention 'the issue' you are having
with your Kitty. Try to Get some* info or feedback to what may be going on
with her.  Or, if no one is available to speak with you, then ask to leave a
message for the vet to call you back at his conveince.

At the very least, you will have 'ran it' by the vet, before spending extra
money for a visit, although, your cat will* probably need to be seen, just
to play it safe, but I'd say, IMO, Yes, there is* something very odd
regarding your cats behavior, and it darn sure wouldn't hurt her to have an
full exam, soon. First things first. If she's in good physical health, then
you'll need to do some independent researching via the internet, etc, for a
good cat Dr. behavioualist, or a very good 'cat whisperer in your area :-).

ML