Need new positive ground inverter?

I have heard of some old solar panels being positive ground but I don't understand how the ground matters in the case of my inverter where neither the positive or the negative is grounded? My panels are grounded to the frame and the rails which is the biggest risk if there is a lighnng strike. My inverter case is grounded but there is no continuity between the case of my inverter and either the positive or negative DC inputs or outputs. Do you have continuity between ground and the positive side of your panel's output? I would test the assumption that you need to limit yourself to a positive ground inverter? That may be an artifact of an earlier design criteria which is now not important. Perhaps someone with more knowledge can chime in?

I haven't read it all but there is an Oregon State University paper on it: SunPower Discovers the “Surface Polarization” Effect in High Efficiency Solar Cells

Also, this thread Replace a positive ground, Sunpower SPR-7000 to a transformer-less inverter has info from youlovesolar refurbed inverters.

Not a plug and only FWIW but about 6 years ago I got an exact replacement for my inverter (a rebadged PowerOne string 5kW), a Sunpower SPR5000 positive ground from youlovesolar.com for when my inverter does eventually go south.
Service was good - real people who were informed and spoke english as their first language. IMO the price was a bit better than fair.

I checked their site just now and they seem to have no 7kW inverters but that's what their site said about my inverter when I bought it so I called anyway and got what I needed.

Might be worth a phone call.

I did call them and sadly they have nothing.