TableView setRowFactory set style bold on row does not bold on OS X

ADDITIONAL SYSTEM INFORMATION :
OS = OS X (fails)
Windows 7 64 bit (works)
xubuntu linux 64 (works)
Java 8 and 13 tested

A DESCRIPTION OF THE PROBLEM :
Using TableView setRowFactory to set style bold on row does not bold on OS X.

A working project to see this behaviour is here: https://github.com/barosanuemailtest/JavaFxEmailClientCourse

This is from a udemy course https://www.udemy.com/course/advanced-programming-with-javafx-build-an-email-client/

The github code can be run as-is with IntelliJ (the project the instructor used) - as long as you have a gmail test account

The method failing is in the class MainWindowController method setUpBoldRows. This is supposed to set the row style to bold.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
The instructor did not use maven so you'd need intelliJ or you could manually set up the project from the github link.

The dependencies were JavaFX sdk 11.0.2, activation.jar and javax.mail



EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The row should show bold for unread email messages.
ACTUAL -
The row remains unchanged - not bolded.

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https://github.com/barosanuemailtest/JavaFxEmailClientCourse
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CUSTOMER SUBMITTED WORKAROUND :
None.

FREQUENCY : always