if you are able to ping management IPs then issue could be something else but common to both controllers.
You can try clear temp files of the management system as well as browser.
You can try different browser
You can try accessing SMU from different system
You can disconnect LAN cable of one of the controller management port and take one seperate LAN cable and connect to your Laptop or desktop directly.......then configure your Laptop IP in Controller IP range......then try to access SMU
If issue only with SMU access but you are able to access CLI with management IP then you can try restarting of management controllers as well
# restart mc a
# restart mc b
or
# restart mc both
Hope this helps!
Regards
Subhajit
If you feel this was helpful please click the KUDOS! thumb below!
***********************************************************************************