My 150/70 is having a strange DC at its input during some nights, not all. Here's an example:
Almost 18V at input. Suddenly around 23.56 it has gone to zero but it came again as you can see.
This MPPT is a part of a bluetooth parallel network, with 2 more 250/60 in which none of them shows this behavior.
What could be this about? It is connected to 3 strings, it's chassis is grounded, as well as the panels frames.
Running fw version 1.54.