I also manually tested the plugin in 1.19, 1.18, 1.17 and 1.16 and couldn't find any issues in these versions.
I did also test 1.15, but while the "time control" works, night skipping doesn't work properly because the Spigot API returns different values for the player sleeping state than in later versions. That's why I set the plugin's API version (the min version it'll run with) to 1.16.