Hi,
Try adding the controller with ip address instead of discovering and enter the credentials with adding options instead of snmp.
Also, check following options:
"options snmp.enable"
"options httpd.admin.enable"
"options httpd.admin.access"
"options httpd.admin.ssl.enable"
"options httpd.timeout"
snmp/httpd.admin/ssl options should be enabled
TLS level on your browser should not be 1 could be 1.2 or higher (but not sure however, you could easily check easiliy in your environment by unchecking all options and then checking one option at a time)
timeout option is by default 300 but I dont feel comformtable suggesting this options since you have leaseline connectivity between two sites however, still getting request timeout error
One more important thing - you also need to check if any software locally on your laptop is disrupting the access (like checkpoing vpn software/mcaffee - logs would be good option to check)
Thanks,
Piyush