I have a MultiPlus-II connected to the Cerbo GX and is fully detected. The issue is that the Cerbo GX and the EG4 LL-S batteries aren’t communicating. I have the Victron to BMS cable between them (Victron Can Bus Cable | VE. Can to CAN-bus BMS type A Cable 1.8m | EG4 LL to Cerbo GX Cable - Signature Solar) and the EG4 batteries configured for the Victron communication protocol.
From my reading online it appears to be a common problem with the v2s?