I lost my 2.4ghz lost connection, 5ghz still working.

2.4Ghz wireless configuration is set on but i cannot see it on my laptop or iphone (less than a meter away).

strange because if i set on the 2.4ghz guest network i can see it

the led on the router is on

This behavior happend after i upgraded the firmware 

I factory reset the router but the behavior maintains.

I bought my router in 2019

I apreciate help

regards

Joao Vaz Martins