nearly no traffic with PTP Bridge

Hi Mikrotik Community!

I have a PTP Bridge between 2 LHG XL HP5 (Distance about 3km) working well for about 4 years.
Since 1 week i have very very low bandwidth and sometimes there’s no traffic possible.

I have checked the LHG’s and the cables for damage
again fine-adjusted the LHG’s
installed the latest RouterOS Updates
tried different frequencies
reconfigured the 2 sites

The RX-TX Signal is at about -79, S/N at about 32dB.
RX and TX Rate are at about 54Mbps.

Does anyone has an idea why there is narly no traffic possible?

Hope you can help me.
Best regards, Jürgen
LHG Problem2.PNG
LHG Problem1.PNG