Oliver in Spain

Is the fault indeed confined to solar charging? I.e. if you disable solar charging, does the inverter operate normally, e.g. battery to load if AC-in is removed?
Does it always show a wildly wrong voltage for the AC output voltage? Bad measurement errors suggest a fault with the -12 V power supply.
If the inverter restarts even when not solar charging, that does look like bad power supply capacitors. See this post if you are able to repair it yourself.
If it's always showing a wildly wrong AC out voltage measurement, I suggest not running it with sensitive loads or for long periods of time.

Very strange that there is no fault code. If you have monitoring software, does it show any faults? Axperts generally write the last fault to EEPROM, which is readable with a pair of commands (QF and QFAULT; see this post for details).
I find the two large bus capacitors last pretty well. It's more likely that the power supply capacitors fail, and this does cause restarting, but it's usually not specific to solar charging. Being limited to solar charging suggests something on the Solar Charge Controller board. I'm not familiar with the high PV voltage SCCs. Something near the output might drag down the bus voltage, which might cause a restart.
The other possibility is the buck transistor (usually an IGBT, could be a MOSFET), either the transistor itself or its gate drive circuit or associated power diode. This transistor is only active when charging. Oliver in Spain, can you charge from utility? That uses the same buck transistor, but not the SCC (solar charger).

This is very likely aging capacitors in the DC-DC stage. Voltronic inverters often fail this way after 2–3 years of continuous use. But lets us ask the fundi on Voltronic inverters for his assessment @Coulomb

Without fault codes try and see if you can manually record the DC voltage as well as current to the MPPT while charging from solar when the inverter cuts out. It might just give a clue as to the reason.

Having failed to end this morning and rereading I now understand (I think) what you meant - I should enter 07.00 as the start time and 08.00 as the end time. Hopefully then at the end of the 8th hour it cut the utility and return to OSO charging. Fingers crossed for tomorrow 🙂

Hi guys
I have found the answer to this question and thought I'd answer it on the forum for incase somebody else has the same problem
The solution is to switch off your phone's mobile data, then and only then will it actually read the 7.2 Max's Wi-fi module. I am almost sure this is because then Android has no other option but to force all communication through the Wi-Fi hotspot, which in this case is the Inverter's Wi-Fi