This might be the same problem as in this OSMC forum topic. If some DVD’s play fine and others don’t then it’s probably not a CSS (= content scrambling system, a copy protection system) problem. I’ll bump that topic again.
Summary of other topic at the time of writing: there seems to be a problem w/ video acceleration. If you disable MMAL and OMX acceleration in “System > Video > Acceleration” in Kodi and the DVd does pay, then you definitely have said problem.