Anything affecting access to essential network endpoint — ad-blockers (including those built into browsers like Brave), strict Firewall settings, network proxies, custom DNS servers — can result in the experience you are seeing. If you are using these, please make sure that the network endpoints listed on https://helpx.adobe.com/enterprise/kb/network-endpoints.html are allowed.
Another think worth checking is if another browser or incognito window works.
If neither helps, let us know and we can investigate further.