Hi there i play it on ps4 pro and iam stuck in a house in Älgnäs surrounded by a few machines… i changed my pumpaction with the meusser because i don’t have any pump rounds…so the inventory says everything is cool and weapon slots are equipt but in game… nothing happend. The Only weapon i can use is the brännboll… looks like i have to try runaway to another place 
and try to go back and get the loot.
Yeah funny i run away with a couple of hunters behind my back to a small ranch nearby and now everything works… 
Is (was) the issue similar/same as this one: Can equip only one main weapon after March 2020 patch [Workaround] ?
If so, Fast Traveling out of the area should fix the issue.