To work with a Wi-fi extender, I set my Wi-fi radio for 5 Ghz to 36 (from the default 153). It cannot work on 153. However, in the next 1-3 days, the value is defaulted back to 153. As I am allowed to change this configuration, it should retain my setting but doesn’t. Usually it changes in 24 hours, but sometimes up to 3 days after.
My Broadband provider doesn’t know the reason, and googling this problem (I can find a similar issue on other makes of router), it offers suggestions which I have tried, but none work.
What will make it retain my setting?