I am a current user of Zwift and I was installing Zwift on a new laptop. The product installed and went thru an update, as expected. It took me to the screen where the software asked me to either login with an existing account or create a new one. I could not advance this screen successfully. Each re-installation of Zwift would automatically put me back to this screen and the red button to try to use the ‘existing account’ option was not a selectable item/field, nor could I tab to the field.
I opened problem 89372 and there were a few email exchanges. I decided to delete chrome and reproduce the problem with just the native Microsoft IE/Edge products, and voila, I could select and click the appropriate login field and this then took me to the Zwift existing user login screen and all went well after that. I reinstalled chrome and it all seemed to work correctly after that as well.
The only products that I had installed were Microsoft windows 10, up to current maintenance, Norton Internet securiey, Spybot, Malwarebytes and Chrome with a couple of extensions including HTTPS Everywhere and Adblock Plus
I know that Chrome is supposed to be as standard-pure as possible but for some technical reason, it would work with IE/Edge. I did not try the workaround with Firefox or Safari