I've actually experienced 'chests not opening' on an un-modded dedicated server... I think it's a 'known issue' that's quite rare but been around for awhile... The solution was to reboot the server and all was well...

According to some reports <I don't mod my game> not being able to interact with boxes comes from the mod that auto picks from close by boxes for crafting and stuff.

Not sure exactly, I think it might be just one part of a bigger mod and only acts up if you use that option?

Usually you need to wait for the mod creator to update the mod to jive with the game post-update OR uninstall the mod(s) until that happens.

Well I could dig around if you post your mod list, I use 42 mods with custom configs and nothing broke.
Played a lot with different modpacks too. But without the mod list I can't figure out which one got broken.
I guess there was no errors in the console ?