PV held to 0.25v below battery voltage mppt 100/30

I have a new Joa Camper made by Pilote with a factory fitted 100W panel. On bright sunny days the system often fails to produce any solar power. Dealer has replaced battery with a better one, fitted Victron 100/30 solar controller but problem persists. Most recently I measured Voc 23.6v but when connected PV held to just below battery voltage, even when battery was loaded to 11.3v still no solar power

Having received no suggestions or replies I thought I’d try again. Currently in South of France with intense sunshine. Been of grid for a couple of days and leisure battery has gone pretty much flat. Unhooked the Victron from PV and battery to see if it could ‘reboot’ but same issue. Over 23V of solar but controller clamps it down to 0.2V below battery voltage.


Obscurely 2 days ago I got a few brief moments of solar voltage whilst driving. Any suggestions would be very welcome