Prima LPR 600 - Salt Cap Stuck?

[OneOfTheSufFolk]

As the thread title mentions, the cap for the salt reservoir refuses to come off when trying to refill the salt. I have tried unscrewing it (counter-clockwise), prying it, jiggling it, etc. and it refuses to budge.

When turning it counter clockwise it smoothly turns until it stops but cannot be removed. Same in the other directions and the same when I try to remove it throughout the turns.

Does anyone know how to remove this thing without breaking it or have an idea of what may be broken?

Thanks in advance!