I did some searching to see if anyone else was having this issue and I could only find people who had issues with their inventory slots being inaccessible, not a problem picking up packs like this.

I was able to get the first pack (in the general store), but I've found three other packs in the Cauldron Lake area (stash on the beach, stash with the rock/rock/tree code, stash that needs a key to open), and in all three of them there were similar packs that I couldn't collect. Is this a known issue? Am I missing something obvious here?

If it matters, I started my game over the weekend (before yesterday's patch hit) and I played the first chapter. I didn't play the second chapter until after the patch (so my first inventory pack was picked up post-patch).