Frequency changing

My mimosa b5 is make change to frequency by itself .
Any option can stop this issue
Or any case can cause this thing
i choose frequency from list oh channel but when i go dashboard i see that center frequency is deference and i get message that tel me the frequency is change

I am going to guess you have “Auto channel” disabled.

In that case probably what happened is you chose a frequency that requires DFS. Basically your radio is required to detects if there is radar or something else using the frequency it’s on and it is required -by law- to stop using the frequency and move to another channel.

In theory, only radar should bump you off of a DFS frequency, but because of several different issues there are such things as False DFS hits. Best way to mitigate them is to have a correct antenna gain set in your radios and be very careful about how you setup your links to avoid issues with reflectivity and other sources of 5 GHz noise that can trigger the DFS issues.