By seeing logs(Message and UserAgent)details, I suspect the problem with Agents registered with TFS Agent or Deployment pools but not sure as I don't have much info about any error code or perfect message.
System
Provider [ Name] Microsoft-Team Foundation Server
[ Guid] {xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxx}
EventID 0
Version 6
Level 2
Task 1
Opcode 10
Keywords 0xx00000000000000x
TimeCreated [ SystemTime] 2019-03-19T08:30:50.06021
EventRecordID xxxxxxxxx
Correlation [ ActivityID] {xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxx}
Execution [ ProcessID] 5900
[ ThreadID] 2500
Channel Microsoft-Team Foundation Server/Debug
Computer machineName.domain.com
Security [ UserID] x-1-5-xx-xxxxxxx-xxxxxxxx-xxxxxxx-xxxx
UserData
Info [ TraceId] {00000001-0001-0001-0000-000000000000}
Tracepoint xxxxx
ServiceHost {xxxxxxxx-xxxxx-xxxx-xxxx-xxxxxxxxx}
ContextId xxxxxxx
ProcessName w3wp
Username VSID {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxx}
CUID {00000000-0000-0000-0000-000000000000}
TenantId {00000000-0000-0000-0000-000000000000}
ProviderId {00000000-0000-0000-0000-000000000000}
Service
Method
Area IdentityService
Layer IdentityCuidHelper
UserAgent Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.121 Safari/537.36
Uri /tfs/casepoint/_apis/Contribution/HierarchyQ
Path UniqueIdentifier {xxxxxxxx-xxxx-xxxx-xxxx-54095xxx48BF}
UserDefined {xxxxxx-xxxx-xxxx-xxxx-xxxxxxxx}
ExceptionType
Message {"method":"ComputeCuid","message":"Cannot generate CUID for User Identity xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxx"}
E2EID {xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxx}
OrchestrationId