Please explain this to me

[SScattered]

https://imgur.com/a/heOKsQu

This is a video a friend of mine send me few days ago. He's working in a Solar system company. The measurements they are taking are directly from the transformer (33KV to 400V). Finally they are measuring the voltage with respect to the earth they have installed for the Solar System. He told me that there's around 7-8m between transformer earth(neutral grounded) and solar system earth. Also please note that, transformer neutral is grounded. We have TT system in my country.
Also, this measurements are taking while this transformer providing power to a factory. I don't know the capacity of the transformer.
As you can see in the video, one of the phases (Black) voltage with respect to Solar system earth showing around 37v and other 2 around 378V.

So my question is why Solar earth and Black phase is having 37 Volts? It cannot be a multimeter issue for sure. Is there a plausible explanation or it's multimeter issue. It might be a bit hard to see that it's 37V, please see the dot.

PS: Black probe at the end of video he's probing it against the SPD terminal (Solar earth)

[Faringdon]

It woudl be good to explain if you had some alligator clips and 4 diff probes, and a 4 channel scope, and could show  volt waveform of Black/grey/brown and solar_earth with respect to transformer neutral.
Or say if you had a battery scope for this, and show all 4 volt waveforms (at the same time)  w.r.t txfmr neutral.

[wraper]

I can say that he measured phases against neutral, not earth. And it's certainly not earth against what he was measuring phases in the end of the video.

[wraper]

So my question is why Solar earth and Black phase is having 37 Volts? It cannot be a multimeter issue for sure. Is there a plausible explanation or it's multimeter issue. It might be a bit hard to see that it's 37V, please see the dot.

He also measured 199V to neutral and around 380V, instead of 240V for other two phases.

[Faringdon]

I think it shows how all the theory surrounding "earth" is often far off.
It isnt the same potential across the land....specially when its sandstone soil say.