Strange Value in Icinga Web when Server of is unreachable using Invoke-IcingaCheckTimeSync

When Invoke-IcingaCheckTimeSync is called on the desired Host via Agent, the Output seems ok:

icinga { Invoke-IcingaCheckTimeSync -Server europe.pool.ntp.org -Warning -10s:10s -Critical -15s:15s -Verbosity 2 }

[UNKNOWN]: Icinga Custom Error was thrown: Custom Exception: ConnectionError

Custom exception occured:
Failed to communicate with the provided server "europe.pool.ntp.org".
A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond

Output in Web Console:

Icinga: 2.13.6 (Master)
Agent:

Name                           Value
----                           -----
framework                      1.10.1
mssql                          1.4.0
service                        1.2.0
hyperv                         1.2.0
agent                          2.13.6
inventory                      1.2.0
restapi                        1.2.0
3itplugins                     1.0.4
cluster                        1.2.0
apichecks                      1.2.0
plugins                        1.10.1

Reproduce the reported Invoke-IcingaCheckTimeSync command on an Agent with europe.pool.ntp.org unreachable, then compare its UNKNOWN output with the value shown in Icinga Web. Start by tracing how this check result is transferred from the Agent to the Web Console, using the listed Icinga and PowerShell Framework versions. Done means the Web Console represents the unreachable-server result consistently with the command output.