@Aslan, Thanks for posting in Q&A. From your description, I know the status is Unavailable which means there is a problem with the Cloud PC's connection due to malfunctioning components.
For ErrorVMAgentUnavailable, it means AVD agent is blocked communicating to RD gateway. Please check if any third-party app installed on the cloud PC may affect this.
Meanwhile, please also check proxy settings for all http requests to see if it works well.
However, if the issue still persists, please open case to collect logs to do investigate on it.
https://learn.microsoft.com/en-us/windows-365/enterprise/troubleshooting#contact-helpsupport
Hope the above information can help.
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