Did you find a solution to this? I have the exact same inverter as pictured, i also have the same issues you described with the timeout on QPIGS retrieval. the QPIRI command works and i can receive configuration data from the inverter, however i get timeouts on the QPIGS like you for status data.
I did read in one of the MPP commands guides that the 48v version of the MPP solar uses the command QPIGS2, not QPIGS, so i am attempting to modify my build files to use this, however so far have not had much luck, if i modify the pisolar.cpp file, then install it to the ESP32, when i come back to check the pipsolar.cpp file it has reverted my changes, please let me know if you were able to solve this.
Hello, I have a similar inverter, but from the Effecta AX-P1 brand, which does not have RS232 but USB2.0 type B, what do I need to connect it to the ESP32