Hi, I have a Deco X50-5G, I am having issues with locking on a 5G signal. I have a Archer NX200 and there is no issue with locking on the 5G signal for this set next to the window

I am not sure if the telco locked this set to 4G, or the X50-5G is having some issues. 5G preferred has also been set. Manual selection has been selected but still it only locks to a 4G signal. I have also tried to reset the device and upgraded to the latest firmware, there is still the same issue. Hope someone can assist. Specific Telco is M1 from Singapore. N78, N1 Band. Sim Card has no issues with 5G when tested in a mobile phone.