@songseop
Good day,
Thank you very much for your time and patience.
Sorry for the delay.
Did both wireless and Ethernet connections have the same unstable issue?
have you tried to change the wireless channel of the 2.4ghz to be 1/6/11 to see if that helped?
How long have you had the modem and when did this issue start?
By the way, where are you located and who is your SIM card carrier?
Have you checked when the internet connection dropped, would the LTE band randomly change as well?
Since we had a beta firmware which could manually fix the LED band, it would help us fix the instability issue caused by auto-band switching;
Thanks a lot.