Launch Windows Defender from the Control Panel. Click Allow an app or feature through Windows Defender Firewall. Add Photoshop.exe and Creative Cloud.exe Click back at the top left. Click Advanced settings.
Click on Inbound Rules. Make sure that you allow on both Private and Public for Adobe Photoshop 2024 and Creative Cloud.
Click on Outbound rules. Look for "Adobe Unlicensed Pop-up". Click on it and then click Disable Rule.
Then relaunch Photoshop and try the Generative Fill again.