Login not working on Firefox, works on Chrome

Hi, May not be a critical issue, but sharing here as others might find helpful. I do not use ZK UI on regular basis and I used it last time months ago. It used to work on Firefox, my default browser. When tried today, it did not. Nothing on logs as well. When tried on Chrome it worked fine.

Both Firefox and Chrome are on latest and I am on Ubuntu 18.04.5