Failure to connect.
I have an iMac desktop, macOS High Sierra, Version 10.13.6. When I log-in to my bank account a blank page titled "HTTP Status 400 Bad Request" pops up. I shut the computer down, restart it and log-in again and it works. But each subsequent log-in results in the Bad Request page popping up until I shut the computer down again and restart. How do I fix this? Thanks for your help.