You cannot drink from the Water Container if you have a water canister in your hot pouch, even if it is empty it just says "you cannot mix liquid types" or something to that effect.
I also have this issue when saving a multi player game. Our temp fix is to do a manual save before exiting then when reloading from the manual save and not the automatically generated "Exit" or "Quit" save. I am on Xbox so not sure if works on PC. So far this works without fail every time.
My friend has this issue when connecting to my hosted game. I have never had the issue so it seems client side. Also it has only been happening since he quit the game whilst standing in/on our base. We have now tried quitting whilst on solid ground to test.