The WiFi connection for my Apollo also seems to be much weaker than for my laptop. It does not find the WiFi network unless the modem is within a few meters of the Apollo. Is that normal?
Is the SD card quality important? I don't know if the old 16GB SD card which I put in the Apollo might be slowing it down. It seems very sluggish even when there is not much processor load.
Orange Pi has a little hanging WiFi Antenna underneath. Try to move it a bit or expose it outside slightly if you can. That may improve signal.
Quality of SD card does not matter, as long as it reads and writes without error and capacity is not faked. Mining process does not require any storage access. If your old SD card burns out, you can just replace it with a new one in 20 minutes by flashing image and popping new card in.