I don’t have this pdf but I think this is just manual with commands to this modem. I opened back in the days support ticket with quectel and they said it’s supposed to be fixed in this version(RM502QAEAAR13A02M4G ) but I have never updated. Those screenshots I got from quectel, but I saw them before online somewhere. This is one of them https://www.quectel.com/wp-content/uploads/2021/05/Quectel_RG50xQRM5xxQ_Series_AT_Commands_Manual_V1.2.pdf
but this does not have “lte_band_priority” in it
Have you tried this command: AT+QNWCFG=? ? Does it have +QNWCFG: "lte_band_priority