So I just booted up one of my 2025 season saves after buying the season pack, and there are no staff members visible on the Phase 3 Personnel screen.
On my other 2025 season save the Personnel department is at Phase 4, and everything is okay on that screen.
So there is a chance that the bug is only present on the Phase 3 Personnel screen, but it might be worth checking.
Dear fellow players! Please check your MyTeam saves, and provide further feedback to this post!