PTP670 modulation mode restricted due to byte errors

Hello everyone;
Am new here and I would like to be assisted on work I’ve done

I deploying offshore one PTP-670 link,
I finished, the link is Up.
But there remains Errors in the Traffic such : Restricted because of Byte error in the wireless link.
What could be the problem?
And how can I solved it?
Sites frequencies below;
Site A : Tx 5820 Rx 5780
Site B : TX 5780 Rx 5820

Regards
Yannick