I can confirm this. Happens both on stable and experimental. It is enough to drop the container item to floor and pick it up again to fix this glitch.

there's another post saying this is due to 0% invisible cans making the slot unsuable.

After dropping container and reequipping it back again I did not notice any cans in the previously unavailable slots.

I think it happens when you drink a soda, while you are using it through the hotbar. I usually drink it the "manual" way, open my inventory and right click drink, and i dont have that kind of a problem anymore. I cant confirm that its going to help for everyone, it did for me.

I never use food or drink with hotbar and I have the same issue. Append a lot with the freshspawn pants. after 3 on 4 slots used, I have to put it down and retack it to make the 4th slot usable.

From my experience, it happens when you consume food or drinks without putting them in you inventory first although there's free slots.
Example: wearing only a shirt and pants, carrying a torch, a battery and a stack of rags, you find a can of soda. Although you got one free inventory slot you don't take the soda but instead you drink it right away.
After this, you'll find the actually free slot blocked and unable to pick up any fourth item.
Dropping and re-equipping the pants fixes it. The slot can then be used again.

If you drink/eat something by pressing F before taking it into your inventory, it dupes the item in your inventory, and it appears as an invisible item. Relogging fixes it.