Deanos

You can check any setting by a long press of the enter button on the unit. Use the up and down buttons to get to the desired setting. Setting 29 is to get the DC cut out voltage level. Use up and down buttons to change the setting and the enter will save the setting displayed.
@GreenFields the APP settings show 26.6V from panels so luckily the 2 panels are connected in parallel but that makes the system not very efficient as you alerted to.

Layman's 2c, use at own risk, or get advice. Some points to consider all the same.
You've got an inverter with a 1200W PWM charge controller. In Winter that's just not quite enough to keep the battery charged. On average, touch and go, under the best of conditions in Winter, it's just-just sort of okay, but most of the time not, and if you're intending to run daytime loads from it as well, then you just don't have enough power generation capability. On top of that your setup is likely not optimal to begin with.
I'm assuming that your 2 x panels are connected in parallel, or it would have exceeded the inverter's max VOC and caused a failure. If this is not already in parallel, you really should change it over to parallel. But your panel's Vmp isn't ideally matched to the inverter. Better would have been to use a panel like the Canadian Solar HiKU6 CS6W405MS panel (x3), because the Vmp spec is better aligned with the battery charging Voltage. Unfortunately you've got a 25% loss of efficiency with the current panel right out the gate.
You could lower the discharge cut-off Voltage to 20V (spec as per the battery), ie. discharge it deeper than the inverter is doing now. And then I think you should change from SBU mode to utility mode, ie. just keep the battery and panels on-hand as a loadshedding solution, without trying to power the whole house from it permanently.
You'd have to do a more drastic upgrade, like changing to a 24V MPPT-controlled inverter, and adding maybe another two panels, before you can start thinking of running daytime base load and then still charging the battery by day for draining at night.