Routing Group Probe failed because one or more routing groups has been building one or more Primary/Secondary replicas too long (ReplicaStatus:InBuild).
Routing Group Replicas are built and rebuilt during cold starts and load balancing. Slow rebuilding of individual replicas can be caused by high load, product or infrastructure issues (e.g.DB contention or data issues, slow/unreliable/throttled network links) requiring investigating and corrective action.
Ensure that all the Front-Ends configured for this Pool are up and running. Ensure backend rtcxds and frontend rtc databases are functioning correctly, ensure indexing jobs are not consuming resources. Ensure network links are reliable, not saturated or being throttled by traffic management mechanisms. If multiple Front-Ends have been recently decommissioned, run Reset-CsPoolRegistrarState -ResetType QuorumLossRecovery to enable the Pool to recover from Quorum Loss and make progress. Please run the Get-CsPoolFabricState cmdlet for more details on the failure.