Batteries discharged on their own and won't connect to inverter/charge up

Hello

We have GivEnergy Battery and Inverter with access to the GE app and online portal. A few weeks ago the power went off. When it came back on the batteries were at 100% but not discharging or charging the home. They just stayed at 100% I hadn't realised this until I checked the app some weeks later.
Last week the Inverter did a software update and rebooted itself. The batteries - that were on 100% suddenly discharged themselves. They show a red light status and flashing green light. The inverter had an orange flashing light. We shut down everything following the instructions on GE database and turned back on but same issue. Tried to force charge in the app using the play button but nothing worked. Took off eco mode and any timed schedules and put the time to charge as all day. Only the solar is providing to the home.
Have turned off the batteries and the isolator batter switch and inverter now back to working but only shows teh blue line from the grid to the centre, and the orange has turned green. In the app we can see solar to home and grid so that part is working.

In the app it shows batteries at 39.7 V and 40V with inverter as idle.

The installer has stone walled helping at all and recently had their MSC certification removed. Everything has worked well up until that stage. We had an electrician check and do a full shut down and restart but nothing helped.

Contacted GE premium and said it is known issue and only option is to charge it with DC charger to bring up the voltage.

Anyone else experience this? Will get a DC charger to do this - have instructions from GE on how to connect it up to charge and bring it to 45V or 50V and then connect it back to inverter and see if that works.

DC direct charge is needed but this is really an electrician job as getting it wrong could be extremely dangerous, plus you need equipment which I cannot imagine would be cheap.
I would consider phoning around local MCS installers and seeing if anyone is willing to do it as a Hail Mary.
If you post your region then someone might be able to recommend an installer.
Whatever happens you are looking at paying money either for repair or replacement.

I should add that the head of GivEnergy field services did do a DC direct charge when faulty cells caused calibration to discharge below the minimum voltages, which successfully revived the batteries until they were replaced due to the failed cells.

Also for completeness on one occasion when the batteries fell out of sync, probably due to the same failed cell, GivEnergy were able to change the battery type to generic Lead Acid and slowly charge them until the voltage was sufficient to bring them back into sync.
If am definitely not knowledgeable to know if that is appropriate to your situation or safe to do but there is at least one third party tool that might allow you to try it.
If you do do it, following more knowledgeable advice, I would definitely only do it during waking hours, closely monitor the voltages during charge and charge very slowly.

thankyou for your reply. Yes this is what we are left with as the only option to charge it slowly to bring it up to 50V.