AutoHUD always seems to use the vanilla height for the hotbar tooltip, regardless of whether that option is enabled.

https://github.com/Madis0/OneBar/blob/main/src/main/java/io/github/madis0/mixin/InGameHudMixin.java#L78

I cannot reproduce this anymore with the latest AutoHUD and OneBar. Either it magically got fixed by me cleaning up, or you did something in the meantime. Hurray for it working fine now, though ;)