Is anyone else getting no loot in containers and/or vendors that don't have any inventory since the update? I'm around lvl 100 and was experiencing this last night after the Gone Fission patch. I was in various places around the map...Not just my usual spots and didn't encounter many other players. I was over-encumbered at the time. I wasn't wanted or otherwise in negative standing with the vendors. I switched servers at least once.
I did a quick search online and didn't see any other complaints of similar issues. Haven't played yet today.
Have you tried testing this on a non encumbered character to confirm that it only happens when encumbered?
Are you using any inventory string mods that have yet to be updated?
Have you tried asking in the Fallout 76 channel of the Bethesda Softworks discord? It is very active and developers often notice and quickly correct reproducible bugs that are posted on that channel.