Just a hint,
I had the same problem/issue as you and I got another hint. I tried almost everything that made sense.
After a while a colluge saide, try https://hostname:443 (No FQDN!) and use in your browser explicit (No Proxy!).
Believe me, after 17 years of using and administrating VMware, my face must looked like a donkey seeing a UFO! But, it worked!
Regards
SeeSite
In my case The suggestion review was very helpful for me. using the FQDN worked perfectly.
Hello
Connect vSphere Clinet WEB by FQDN name
Thanks
You also need to have proper name resolution. The ESXi hosts should be resolvable from you box where you run browser under names exactly as visible in vcenter.
Thank you because I spent hours trying to get this to work.
Resolved by using hostname:443 for whatever reason it worked.
I had the same issue. The workaround that worked for me was I logged in to vsphere with the local administrator account vs logging in with my domain credentials.