I know this is an old thread, but I'll put this here in case someone else runs across this issue.
These symptoms, unable to connect to web UI from a browser on the same subnet, but can from a browser on a different subnet, will also manifest if the system on the same subnet as the esxi host has jumbo frames enabled, but the vswitch on the esxi host to which you're trying to connect does not. Web UI connectivity from systems on the same subnet is restored by either reducing the MTU on the systems on which you're running the browser, or by increasing the MTU of the vswitch on the esxi host to which you're trying to connect.
I have replicated this on esxi 7.0 Update 3 with the following rig:
HP DL-360 <-> Mellanox CX-5 <-> Arista 7050 <-> ASus XG C100C <-> Windows 11 Chrome
HP DL-360 <esxi 7u3> <-> Mellanox CX-5 <-> Arista 7050 <-> Mellanox CX-5 <-> HP DL-360 <-> esxi 7u3 <-> Windows 10 Chrome
Cheers!