If software cursors is used and a rotated mode is set with, for example xrandr -o 1, The cursor disappears.
Tested with current git master (Option SWCursor True) and current MPX which has the SWCursor hardcoded. Works with both.
I _think_ this was fixed with 96ef0f78438b60436c3940817980a3ab4070c7e8.
Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct.