Had the same issue. But you can double carry. Just make sure you put the weapon in your hand manually to the ground. And also make sure not to be too near to a table, a chair, a car or anything else so that te weapon does not glitch beneath it.

I always choose a open area without any furniture or objects near the place i drop the weapon - since that never lost a weapon again.

Had a similar issue while double-carrying. Had Mp5 in my hands and found two cans of food in one house.

1. opened first can with stone knife (drag/drop knife onto can, select option from context menu);
2. initiated Eat All from context menu, without dropping the mp5 first. gun was put down and character began to eat.
3. while eating animation, i opened second can (same methode as in point 1).
4. when eating animation has ended i tried to initiate Eat All on second can.
5. there was no reaction for several seconds. Then, i got "cannot interact/pick up item" error and eating animation on second can began.
6. by that time, mp5 was gone. it did not come back on reload, it didn't appear anywhere around the building i was in.

It happens all the time, disappears. Its best to step back from the well. Drop the primary in your hands to the ground then step forward to the well.

It will save you from losing weapons. So many guns in the well. I can only wonder how many over the patches.

This also applies to being to close to a tree, dropping your yellow protector case out of your bags. It now is embedded into the tree and are unable to {take} item out of the tree.

SO the best way to avoid this is place the items from your hands in an open spot on the ground prior. This way they wont go poof, or stuck in a tree.

Hope that helps some people.

Same applies to all objects in the game.

They disappear. But technically you still have your weapon in your hands.

If your weapon disappears you have to relog immediately and you get your weapon back.

Just happened to me aswell.

1. dual carry weapons
2. kneel infront of pump
3. take canteen into hands so that the carried gun drops
4. the gun disappears (presumably into the pump)

relogging did not fix the issue for me.