I can't dial a course using the OBI. When I tune a VOR in NAV1 and select EFIS to "VOR" mode the EFIS shows appropriate VOR and DME, but if I rotate the OBS the CDI (course deviation indicator) doesn't move at all, rather stays center the whole time. How do I manually fly VOR courses/airways if CDI doesnt move? My conditions are set as follows:

IRUs properly aligned
NAV radio tuned to valid VOR
EFIS says "VOR L" although not sure if this has anything to do with it or how to change that
EFIS selected to "VOR" mode

Any ideas??