RM521F stuck in 4G+ mode (T mobile)

The model # RM521FGLEAR05A02M4G

I used the RM521F in Mcuzone 5g to ethernet board and it worked great…i had 5g SA bands 41, 25 etc
I am very close to a T mobile tower
I decided to try this RM521F inside the GL.inet X3000 router (it uses a RM520N)
I swapped out the RM520N with the RM521F (bcuz of available higher number of carrier aggregation)
At first it shows 5g SA mode (band 41,41 or 41,25 etc)
But when i connect to tower, it only goes to 4G+ mode
I have tried forcing AT commands for 5g SA modes and it won’t work.
Here’s what i tried…
AT+QNWPREFCFG=“mode_pref” (Check current network search mode)
AT+QNWPREFCFG=“mode_pref”,AUTO (Set network search mode to automatic)
AT+QNWPREFCFG=“mode_pref”,NR5G (Set network search mode to 5G/NR only)

AT+QNWPREFCFG=“nr5g_disable_mode” (Check to see if SA or NSA NR5G is disabled)
AT+QNWPREFCFG=“nr5g_disable_mode”,2 (Disable NSA 5G/NR only)

AT+QNWPREFCFG=“nr5g_band” (Get current 5G/NR bandlock settings)
AT+QNWPREFCFG=“nr5g_band”,41:25 (Example: Lock to 5G/NR bands n41,n25)

I also tried masking the 4G LTE band so as to force it in 5g SA mode : then it doesn’t connect to tower.

The only time it works is if i let it go with 4G LTE

I have tried to reset the modem : AT&F0

Nothing has worked thus far.
I don’t have a factory firmware to flash the modem, but that is what i may need.

Is there anything else i can try?

Dear @caymann
You use the same module and same SIM card, right?
Did you search the 5G network in your test environment?
AT+QENG=“neighbourcell”

Yes i have strong 5gSA signal…SINR is 26
May i have the modem firmware please?