I totally agree with you. Are you on higher version than ECC 5.0? because I checked in ECC 6.0(other server) and its working fine (Only OBT2 settings and no VOTXN) but we are on ECC 5.0 and I am not sure if this version don't support but we are having this issue. I could not find any SAP notes either.
Yes - I cant find these texts in XD01 or XD02 either.