I looked into this and see that the Quickbooks Pro Timer app has not been updated since 2013. What Intuit may not realize is that it has worked flawlessly as last written in 2013 with each successive version of Quickbooks Desktop through v2020. I'm holding off on upgrading the Quickbooks Desktop version beyond 2020 until Intuit includes support for time imports from the Quickbooks Pro Timer app. Ideally, Intuit will also update the Quickbooks Pro Timer app as well for better compatibility with newer operating systems.
