One possible issue with using the SA Pi if you are powering it from the 48 vdc battery bus is possibly creating a ground loop between the Pi and the inverter. Normally devices connected via a USB cable have independent power supplies (i.e. printer, cell phone etc) and do not share a common positive. If you have one or more working USB ports on the Pi you can extend it with an USB Hub.
You can connect SA/Pi to the Wifi port on the AIO using pins 7&8 of the Wifi port connected to SA with an USB to RS485 Converter.
The one with the brown and brown/white is connected to the inverters Wifi RS485 port. Pin 7 is brown/white and pin 8 is brown. I used an extra ethernet cable, cur the RJ45 connector off one end, stripped the outer insulation off and expose the 4 twisted pairs. I use one wire pair for the inverter and the other wire pair for battery monitoring
View attachment 189844
USB-RS485 Converter