I've realized you have been necroposting on posts, which mean posting on posts that have been inactive for over a month. I'd just like to say that this is against the rules, and you can get warned on the forums for this.
Try /gamerule naturalregen (or something like that) true
You may have accedentaly set it to false, if that doesn't work it has to do with a plugin, tell me witch ones you use
Have you tried uninnstalling and reinstalling your plugins, I think minehut keeps your save files, I discovered files from plugins i deinstalled a while ago
Servers turn off if nobody is on them, if that's not what's going on I would like a ss of yoyr logs, I can't just tell what's going on. Play on your server untill it happens again and send me the log or a screenshot of (logs can be found at file manager>logs>latest logs)
Thanks!
Make sure your server isactivated, if it's not tell them to go to the lobby and in there do '/join (world)' ad wait 2-3 minjutes if they don't get TPed they should try again
Did you reset your world on purpose, then we can't help
But check if you changed your world name at server properties, change it back to world. There is also an isue with if minecraft updates, then I can't help you