Enforce the modem to connect just to lte

can I to enforce the modem to connect just for LTE network and not trying to connect to 3g when the lte signal is low?

my network is LTE only and i think the modem is trying to connect 3G when the signal is low and i want to cancel it.
my moden is ec21, i got ep06 too.

Try the AT+QCFG=“nwscanmode” Network Search Mode Configuration


i try it and it’s not working.

Check you SIM card first. What if you swich to anther SIM card?
If it is still not working. I am afraid you have to email to support@quectel.com