AP Describes Musk’s Coup as ‘Penchant for Dabbling’

denying them access to their own personnel files, with their pay history

I recently learned that you can expect this out of absolutely every employer.
If you can access it, save it.

Screenshot it, write it down (if you can only access it at an electronics restricted workplace) and keep your data under your control. Because they might just delete their records whenever they feel like and ask you to give them the information for billing purposes.