Neutral to Ground PV is Hot

I have a PowMr 5k inverter charger in my system which has been up and running for a while in an off grid cabin.
It seems to operate ok for the most part, I can power the cabin, startup generator to charge batteries if its cloudy for a couple days etc.
One question I have been trying to resolve since install is that if I test between the PV input neutral and any ground wire either in the inverter or the panel, I get a reading of 199v. This makes no sense to me but maybe it is completely normal. This happens even after I have measured total incoming volts at say..220v or 170v or whatever.
I do not have allot of confidence in this inverter and would not have purchased it if I had seen how limited the manual and support was. I really didn't know until I recently downloaded and read the EG4 manual.
I even tried contacting the seller, but received no definitive information. There is also contradicting information in the documentation. In the one sheet describing the inputs and outputs and operations it notes "Only the Live and Neutral wires will be connected to the Output Terminal Block, the Ground will be connected to the scre w terminal." I tried both ways but it made no difference.
I found other versions of this document which omitted this statement but included a statement about the requirement with lithium battery to first connect the PV turn unit off.. then connect the rest of the system.
At one point someone answered my question that it was normal to get voltage off neutral and ground on the PV.. another time I was told "something is wrong"
I am very experienced with AC power having wired multiple full houses but little DC background other than the occasional vehicle work.
I'm pretty certain at this point I will be replacing it with probably an EG4 but still would like to know.

I think there are some terminology issues here. The PV input should be + and -, not neutral and ground. Neutral and ground should be pertaining to AC only, not the PV. Could you please take some pics of the spots you are actually measuring? It sounds like what you are talking about is ACinput (ACin) and ACoutput (ACout), nothing associated with the PV?

Nope, I'm not talking about AC In or Out. Its the PV in. I have + and - (which I incorrectly referred to as neutral) its the negative when connected to any bare ground wire in the system that reads 199v. Again, system is fully functioning. AC in works AC out works Battery charges on generator or Solar.

I think what you are referring to is what is called "ripple current", which is a well-known problem. Apparently, it is somewhat design related, because it has been mentioned before as a problem with some AiOs. Here is an excerpt from that link...

There are very small value filter caps on HV DC node so there is a lot of 2x AC out freq ripple voltage on them which heats up electrolytic caps reducing their lifespan. It also gives them little to no surge capability. PV input caps are very low in capacitance so there will often be ripple getting through to PV panel loading which reduces panel maximum power point output current.

@mikeyoungvcu89 I just posted a similar question. I am not sure which ground to use for a receptacle on the AC Out. The one next to neutral or on the outside of the case. I was planning on testing it to charge a Tesla with the 15 amp plug but I think a bounded neutral is required and I am not 100% sure how/if that can be done with this inverter running on a mobile 48 volt battery back/generator I built.

Your dc panel input is not referenced to earth ground or AC live or neutral

If you put a meter across a PV panel output and AC earth , live or neutral you’ll get a completely erroneous reading , ignore it.

As

MichaelK​

Noted
There are very small value filter caps on HV DC node so there is a lot of 2x AC out freq ripple voltage on them which heats up electrolytic caps reducing their lifespan. It also gives them little to no surge capability. PV input caps are very low in capacitance so there will often be ripple getting through to PV panel loading which reduces panel maximum power point output current.

This voltage and amperage can be lethal mainly as it is an unexpected condition. Avoid all unprotected contact between the inverter PV input (-) and any earth ground particularly when the panels are disconnected. The inverter PV (-) input will be deadly dangerous. This was found to be the case on a Growatt SPF5000ES with an internal grounding screw removed and insulated. Extreme caution should be observed of this unexpected condition.