So we can follow up with you on this please turn on 'Enable Logging' in PokerTracker 4 via 'Configure -> Options' and then restart PokerTracker 4. Next reproduce this issue, take a screenshot of your table(s) and create a support bundle via the 'File -> Create Support Bundle' menu option in PokerTracker 4. When that file has been saved attach your support bundle and screenshot to a Support Ticket. In the meantime you can also revert to PokerTracker v4.18.4 here and let us know if that version is working for you.
If you want to get a build that addresses this issue before it is made public, you can open a Support Ticket with a link to this thread, and we'll share it with you once it is available. Adding a Support Bundle, a screenshot and the original HH file(s) will make it easier for us to find the solution.