"You need a gun" trophy bug+possible fix!

TL;DR - struggling with this trophy? Disconnect your PlayStation from your online network - reopen the game and then purchase your final weapon upgrade again.

I hope this helps as I can see a few people out there who struggled with this like me.

During medium security playthrough, I fully upgraded baton + hand cannon - no trophy was given. A bit of research online shows alot of people having issues with this.

I thought, what the heck - I'll try again on my next NG+ maximum security playthrough....

Same again - built up the credits, fully upgraded a couple more weapons - no trophy. At this point I'm thinking I'm doomed.

I enjoyed the game a fair bit so started a brand new save and played all the way until I could afford to fully upgrade the hand cannon (just before the SHU) - got to the reforge and purchased the final upgrade - no trophy again.

Closed the game. Disconnected my PS5 from network. Opened game. Loaded latest save file. Purchased final upgrade for hand cannon. Jacob got his fully upgraded gun and and finally got the trophy.