Hey there!
If there's lag it sounds like your server is having problems keeping up with things. Ask your server admin what the situation is, they should be able to let you know when they'll fix it.
You can find your server admin's contact details on your server's about page (for you that's https://techhub.social/about).
Just to check though, have you tried a different app? The official app isn't that great, you might prefer a third party app like Toot! or Ice Cubes.