[why is changing between versions not allowed]

my server has been completely broken and unplayable since the 1.16.1 update was forced. the thing is, plugins don't update instantly, so some servers that rely on plugins break - including mine. I don't know if it's a problem with the world generation or whatever but it seems to get stuck in "preparing start region for world" in logs. is there a way to go back to 1.15.2?????? starting server from online/ingame doesn't work, it goes from downloading -> unzipping -> starting until it eventually shuts down.

[Update USkyWars please]

https://www.spigotmc.org/resources/uskywars-beta-skywars-plugin-1-8x-up-to-1-13x.70686/

the latest version listed here is 1.9.2, yet checking logs the version on MH is 1.7.0

it throws an error in logs every time I start my server and just doesn't want to work - ppl on discord say that updating it would be best but of course I can't add custom plugins on MH, so here I am.