Game Slowdown when doing Pure resource mission

Hi not sure if it’s just me but I get massive slowdown of the game when doing any The Pure resource mission Random encounters, there are usually only 3-4 enemies on the map but the map is very laggy and camera difficult to move.

If I battle through and complete the mission the game returns to normal but it’s almost unplayable during these missions.

I’ve tried reloading game and still no joy and it’s done it on 2 missions now.

I get a massive slowdown on any scavenging missions and any on that particular style of map.

This includes ambushes and special missions.