[2022] Ps4 bug I encountered, I cannot select a tier 5 mod for the boomstick, I've tried switching classes and restarting the game, and it won't let me switch off of fear the boomstick.

We have discovered the cause of the unchangeable modification issue. It's caused by the Display Area settings on the PlayStation 4.
While we're working on a permanent solution, here's a workaround:
Go to Settings - Sound and Screen - Display Area Settings - and enlarge the boxed area.