My Wifi 5g channel jumps back

Recently my wifi 5g has not been working properly and I found out the cause is that my wifi 5g channel is at channel 157. Every time I switch the channel using the Xfinity app or from http://10.0.0.1/, my wifi 5g works for 20 to 30 sec then the channel switches back to 157 causing my internet to become unstable. I used the wifi analyzer and found out that channel 157 is congested and I wonder why the router is picking channel 157 as the primary channel.