Thank you for asking this question on the **Microsoft Q&A Platform. **
That is not a particular configuration for AVD, that setting you have to do it an OS level and RDP session timeout.
- Press Windows + R and type gpedit.msc
- Navigate the tree view on the left to Computer Configuration/Administrative Templates/Windows Components/Remote Desktop Services/Remote Desktop Session Host/Session Time Limits
- Disable all four settings
Hope this helps,
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