
I suggest trying to set Configure Start Pages group policy.
GP path: Windows Components/Microsoft Edge
GP English name: Configure Start pages
value: <example1.com><example2.com>
For the Registry key setting:
Path: HKLM\SOFTWARE\Policies\Microsoft\MicrosoftEdge\Internet Settings
Value name: ProvisionedHomePages
Value type: REG_SZ
Value: <example1.com><example2.com>
If Configure Open Microsoft Edge With policy is enabled then set its value to Load a specific page or pages.
Reference: Configure Start Pages