To work around this problem, open a new terminal window and do:
cat /dev/kprint
This works because, according to the kprint discussion in cons(3), "if (the) console is a graphics screen, the data is sent either to the display or to kprint, but not both."
Another more permanent solution to the problem is to put
cat /dev/kprint >/dev/null >[2=1]
somewhere in termrc (see cpurc(8)).