After upgrading my server (issue also occures in singleplayer) to 1.18, all of our chests didn't render and chests and shulkerboxes did not have any contents anymore. The chests I've opened started rendering again when I rejoined the chunks but there still wasnt any contents. I tried it with another account, still no contents. Luckily I have a backup. I talked to some people and they experienced that issue too.
I would mark that issue as urgent.
Beds also dont redner anymore, but other tileentities do.
I couldn't find any open issue, so I created this new one.