Disruption of Chrome Cast Connection

I have just bought a Nighthawk Routers with WiFi 6 with 2 satellites. I managed to connect it to my Google Chrome Cast, but it keeps disconnecting. Even sometimes I cannot connect it again, although sometimes I should reset my Chrome Cast to re-connect.
I believe I have checked all basic things such as:
- I have checked that both my phone and the Chrome Cast are connected to the same WiFi.
- Both phone and Chrome Cast are in 5 GHz WiFi.

I have disconnected both phone and Chrome Cast from the Nighthawk WiFi and connected them to my main router to check whether the problem is with the Chrome Cast, but with the original router the connection works perfectly without interruption.

Could you please advise me how can I fix this issue?
If this device has any compatibility problem with Chrome Cast, then I would like to return the system as I use Chrome Cast a lot.