The problem occurs in all 5 styles on this end.
There were no changes to the styles whatsoever, and the problem described in the title.
The only changes that were applied were in the code itself:
Following the application of these parameteres, the strange behaviour of the styles began:
"AutoSizeColumnsMode = Fill"
"AutoSizeRowns = True".
I will also include a video showing how the styles behave in order to clarify the problem.