I was hoping I wouldn't resort to this, but here we are.

Unfortunately, the title API in the early 1.19 builds got butchered. As a result, AT and other plugins that use this have started kicking players from the server. Whilst this issue has been fixed, many have not updated their Spigot builds or do not know how to. For the time being, I feel that my best call is to disable this feature temporarily since it is causing major issues that I believe are causing too much of a hindrance.

To quote my announcement on Discord - PLEASE ENSURE YOU ARE ON THE LATEST VERSION OF SPIGOT 1.19. If you are with a shared hosting site, PLEASE ask them to make sure Spigot is updated regularly and properly. Unfortunately, this appears to be the major cause of the issues - everyone rushed to add the new 1.19 Spigot, then completely forgot about it. I do manage these kinds of updates in my own job, these are vital and MUST be taken seriously. If your host is not updating, then they are the ones sabotaging your server and compromising its safety. If you do not believe your host has updated their Spigot build, please inform them through whatever support means they have available (ticket, LiveChat…). This is the main reason why people are experiencing this issue in the first place.

If you do not experience this issue, you do not need to update. If you are on a newer version of Spigot 1.19, you do not need to update. If you're lost... maybe it'd be worth updating.