It works fine in Ubuntu 16.04 so after a bit of testing, if you copy the ioquake3 file from usr/lib/ioquake3/ in 16.04 and paste to usr/lib/ioquake3/ in 18.04, make sure it is executable, then it worked for me
It works fine in Ubuntu 16.04 so after a bit of testing, if you copy the ioquake3 file from usr/lib/ioquake3/ in 16.04 and paste to usr/lib/ioquake3/ in 18.04, make sure it is executable, then it worked for me