(4.8.3) P95, P99 of write (but not read, nor average latency) are the same across all shards - very unlikely

[mykaul]

Installation details
Panel Name: 95th percentile write latency by Shard , 99th percentile write latency by Shard
Dashboard Name: Keyspace
Scylla-Monitoring Version: 4.8.3
Scylla-Version: 2024.1.12

It's an Alternator workload, might be related, but I can't believe the P95 and the P99 write latency is exactly the same across all shards.
The average latency isn't, and reads are all somethat different.

[mykaul]

Moreover - by shard/instance/DC - I get the same value...