Shorted Battery - now Switch board Voltmeter no longer same same multimeter reading

[Caroline Joan]

I managed to Short my batteries (a moment of carelessness) - now Switch board Voltmeter no longer same as multimeter reading.

Switchboard says 12.0v but when I test Battery bank (3 x 170ah batteries) the reading is 12.8v.

The solar generator regulator says the batteries are fully charged and the regulator shows as being in float state.

Any idea what I can do to fix switchboard voltmeter reading?
Prior to me shorting Batteries the Switchboard and a multi-meter reading were always similar.

I must have cooked something.

I just noticed that if I put the connect multi-meter to buzz bar behind the switchboard I get 12.0 volts. So maybe somewhere between batteries & switchboard I'm now using .8 volts - just doesn't seem right?

The switch board is the standard for a Beneteau 50ft

Normally when Solar charging the volts show on switchoard around 13-14volts. After shorting they only showed 12-12.3volts.