Try mo to:
AT+QMBNCFG="AutoSel",1
AT+QNWPREFCFG="nr5g_band",1:2:3:5:7:8:12:20:25:28:38:40:41:48:66:71:77:78:79
AT+QNWPREFCFG="nr5g_disable_mode",0
AT+QNWPREFCFG="mode_pref",AUTO
Then reboot router.
Temporary block updates. Not full proof and not tested.
login via telnet/ssh and run all this commands.
fw_setenv TR069_INFO "MODEL=P28OPEN;OUI=010203;tr069_enable=0;inform_enable=0;acs_url=http://localhost:9091"
fw_setenv FOTA_INFO...
Dipa siguro enabled ssh mo.
login ka ulit via telnet.
tapus run mo to.
fw_setenv dropbear_mode 1 && /etc/init.d/dropbear start
Edit Invalid credential pala.
baka may typo sa password mo try mo ulit palitan.