Ran into an issue with a customer installing new cloud connectors on 2019 with the latest connector software. It would get to the prompt to login with the browser, open the browser selector to choose between IE and Edge and the cloud connector software would just close. You could successfully login with Edge, but then give you an error on localhost:8080 because that software had closed. The fix was to remove IE from the machine with

dism /online /Remove-Capability /CapabilityName:Browser.InternetExplorer~~~~0.0.11.0