We have a web based application that prints to Dymo label printers. We've noticed that if the user has previously had the older Dymo software DLSv8 installed, then uninstalls this and installs Dymo Connect they can't print through the Web Service.

Firefox works fine in this scenario, but Edge and Chrome don't. Sometimes. It's intermittent, some users with DLSv8 installed prior work fine in Chrome. 

There are no extensions showing in Chrome.

Is there anywhere you can think of that there could be some remaining traces of DLSv8 in Chrome that need to be purged? On MacOS the DLSv8 certificate had to be manually deleted from the Keychain before installing the new one.

Firefox needs to be installed on the computer prior to installing Dymo Connect else it doesn't work in Firefox.