Well, there could be a few reasons, but more context is requested! May i ask, Does it give you any errors in minehuts chat or in general? If so, please take a screenshot of the message and send it in here.

I made myself an operator in my server, and it sends me to the lobby rather than the server. When I type /join server, it doesn’t allow me to join. Any reason for this?

You could always buy a custom plan if you have the money too, which removes that time limit. Though i dont recommend putting your hand in a blender, that would not make for a nice smoothie-

Also, Minehut Servers, while they might be free for you personally to create and activate on Minehut, they aren't free for Minehut themselves. Minehut loses money when someone starts their free server, As that is using their server resources, which also cost Money to maintain and keep running. Minehut currently has over two thousand Minecraft servers running at once. Having that many servers tend to add up overtime, especially when some are not on a plan. They had to reduce the time that server is online to encourage users to want to buy their Pre-made or Custom server plans, If they wish to be able to remove the Limit. If minehut didnt feel the need to make the time limit happen due to financial troubles, then they wouldn't have made that decision.  Do note, im not saying you dont have a right to miss or be upset about the time limit, i just wanted to just put it here to let you, or anyone wondering know why the time limit is put in place.

send "%{warplist::1}%" to player

you replace 1 with the position you want from the list