No graph due to german special character in performance data

Hello everyone

I use the command “invoke-icingacheckPerfCounter”
to our Hyper-V server, among other things, the “logical processor”
Monitor utilization
Everything works so far. Unfortunately, Graphite does not show me any graphics
This is probably due to the “German” special characters in the command
\Hyper-V Hypervisor - Logical Processor(_total)\% Total Execution Time"
The character " – " is not a hyphen but a “thought stitch”

Icinga web show this " �?? " in the Plug in output
Does anyone know a solution
I’ve already tried to use the “numerical values of the performance counter”
same Result

greetings from germany

Stefan