Did you try rebooting your Mac? See this article on uninstalling/reinstall, it worked for some people.
https://ttlc.intuit.com/community/installing/help/remove-uninstall-turbotax-for-mac/00/26050
from this thread, https://ttlc.intuit.com/community/taxes/discussion/turbotax-deluxe-2017-for-mac-is-stuck-in-a-downlo...
@macuser_22
