1-Ensure Microsoft Edge GPOs are Available
Download the templates from https://www.microsoft.com/edge/business/download
2-Verify GPO Configuration
Computer Configuration > Policies > Administrative Templates > Microsoft Edge
User Configuration > Policies > Administrative Templates > Microsoft Edge
3-Check GPO Link and Scope
4-Force Group Policy Update
CMD> gpupdate /force
5-Check Group Policy Results
CMD> gpresult /r
6-Verify Permissions
7-Check Edge Version Compatibility
8-Review Event Logs
Application and Service Logs > Microsoft > EdgeUpdate for Edge-specific logs.
Windows Logs > System for GPO-related logs.
9-Network Connectivity and DNS
10-Check for Local Policies Overriding GPOs
gpedit.msc
11-Clear the Group Policy Cache
C:\Windows\System32\GroupPolicy\
CMD> gpupdate /force
12-Ensure Edge Policies are Supported on the OS Version
By using these step-by-step, you should be able to identify the root cause of why your Microsoft Edge GPO is not being applied. If none of these steps work, you might want to test applying a simple GPO to ensure that GPO application itself works on the machine.