Conditional formating on a visual's title property works perfectly while in PBI Desktop but no longer appears after publishing the PBIX to the Service. Just noticed this issue as of about 10/24/2019.
I have made a test on your issue but couldn't reproduce it. This seems to be a temparary issue. Please follow steps below and check if this issue persists.
1. Press ctrl+F5 to refresh the browser page.
2. Clear the cache.
3. Clear the cookies.
If this issue persists, I would suggest you to create a support ticket here.