Multi WAN: dpinger shows daily loss

[lyceum]

Dear members

We have 2 Fiber and 1 Coax WAN-gateways for our school.
Half of our school exits via GatewayGroup1 the other half via GatewayGroup2.
In Gatewaygroup1 our first Fiber (PROX1) is Tier1, PROX2 is Tier2, Coax = Tier3
Trigger is set to 'Member down'. This used to be "Packet loss or high latency" but when that was set our coax used to take over too often.

If we look at the Gateway-logs we see something strange happening.
Every day we get a message about loss on our lines. Sometimes coax is also involved.
Is this 'normal' behaviour or is there something wrong?
Testing on our fiber and hardware via the TelecomOperator revealed no issue.

2022-09-20T07:06:43   WAN_PROX2_Fixed 8.8.4.4: Clear latency 6757us stddev 135us loss 20%   
2022-09-20T07:05:58   WAN_PROX2_Fixed 8.8.4.4: Alarm latency 7021us stddev 1824us loss 21%   
2022-09-19T07:06:40   WAN_PROX2_Fixed 8.8.4.4: Clear latency 6763us stddev 84us loss 16%   
2022-09-19T07:05:58   WAN_PROX2_Fixed 8.8.4.4: Alarm latency 6752us stddev 130us loss 22%   
2022-09-18T07:06:36   WAN_PROX2_Fixed 8.8.4.4: Clear latency 7128us stddev 1933us loss 18%   
2022-09-18T07:05:56   WAN_PROX2_Fixed 8.8.4.4: Alarm latency 6903us stddev 1072us loss 22%   
2022-09-17T07:06:18   WAN_PROX1_Fixed 8.8.8.8: Clear latency 12176us stddev 141us loss 16%   
2022-09-17T07:06:15   WAN_PROX2_Fixed 8.8.4.4: Clear latency 6884us stddev 752us loss 15%   
2022-09-17T07:05:47   WAN_PROX1_Fixed 8.8.8.8: Alarm latency 12189us stddev 104us loss 21%   
2022-09-17T07:05:32   WAN_PROX2_Fixed 8.8.4.4: Alarm latency 6785us stddev 176us loss 21%   
2022-09-17T04:12:38   WAN_PROX2_Fixed 8.8.4.4: Clear latency 6799us stddev 397us loss 5%   
2022-09-17T04:11:46   WAN_PROX1_Fixed 8.8.8.8: Clear latency 27677us stddev 9738us loss 5%   
2022-09-17T04:08:47   WAN_PROX2_Fixed 8.8.4.4: Alarm latency 7169us stddev 1860us loss 22%   
2022-09-17T04:08:46   WAN_PROX1_Fixed 8.8.8.8: Alarm latency 12141us stddev 85us loss 22%   
2022-09-16T07:07:02   WAN_PROX1_Fixed 8.8.8.8: Clear latency 12167us stddev 165us loss 13%   
2022-09-16T07:06:54   WAN_PROX2_Fixed 8.8.4.4: Clear latency 6760us stddev 105us loss 16%   
2022-09-16T07:06:43   WAN_PROX2_Fixed 8.8.4.4: Alarm latency 6744us stddev 129us loss 21%

If anyone can point me into the right direction, its very much appreciated.