Command blocks not working on Server

On my Aternos server, command blocks DON'T WORK...

I enter the command into the command block and click 'Done' and when I click it again the command just vanishes, like I had entered nothing.

This is getting annoying as long commands won't work in chat.

Please help (I reinstalled 2 times, also I have command blocks enabled in the Aternos settings and the gamerule is set to true)

help pls

...?

Quote from Henery

What software are you using?

PaperMC 1.12.2

Quote from Henery

I just checked, and I don't see any problem. Maybe check "special permissions" you have?

I'll try it tomorrow to see if it works