Game slowdown PS4

Hi, so I’ve been playing this game on and off pretty regularly for about 2 years ago. The first few months were fine but I’ve noticed a seriously bad issue that pops up alot
The game ends up slowing down, either on single player or multiplayer to the point where its seems the frame rate itself is slowing down. Everything to my character, the machines and the menu all slow down.
I encounter this normally every play session, sometimes it’s not bad and can go away in a few minutes, other times it just sticks about until I come off the game or even crashes the game sometimes. I’ve found this happens when I sometimes encounter a big group of enemies, enter Ostervik in the forest region, enter the Himjfall region and also happen randonly at times. This also happens to my friend who’s also on PS4 as we’ve crossrefernced what happens on both consoles. I’ve hoped this to be fixed from the multiple updates but it seems that its an issue affecting everyone I know with this game

Completely forgot to add the town of Osterhallen in Himjfall, this is one of the worst areas instant slowdown the moment I load in to the area