PTP550 DCS select frequency that is not in the list

We are using PTP550 with the firmware 4.5.5.
The DCS choose frequencies which are not in the list.
Is there a way to really limit the choice to the wanted list ?

Hello Ichevouline,

do choose fixed frequencies in case there is clear channels available for you.

That this the best to work.

Sincerely yours,

Niragira Olympe