There still seems to be a bug in administrating/organising fonts and font families. While other applications display a font family properly and make all assigned typefaces of the family available in a proper drop down menu, publisher struggles in finding a family and belonging fontfaces. In the example you can see how InDesign (and many other applications) displays the Adobe "HelveticaNeueStd" Family with all typefaces in a proper menu ... an than have a look at the mess Affinity Publisher produces from the same family - this is very hard to work with ... nearly every (not all) typeface seems to be a seperate font family ... a nightmare ...
Cheers, Timo