NBN smart Modem 5G wifi unstable

[Rez01]

I have telstra NBN smart modem gen2. Everything is good except for the 5G wifi. The 5G wifi seems to disappear time to time. And the fixed devices like google home, fire tv keep getting disconnected from the 5G wifi even though they are right next to the modem. As a result I cannot use 5G wifi and forced to use 2.4G. My question is what is point of having 5G wifi ?

[cf4 · Accepted solution]

This could be due to the 5G WiFi switching to a DFS channel. Try selecting a non DFS WiFi channel in the modem's 5 GHz WiFi settings.

[Rez01]

Thank you very much. Selecting non DFS wifi channel solved the problem.