Have existing App, which was working all OK, but either with last SfComboBox update and/or iOS 13, the dropdown entries font is not NON-STANDARD. Of course in iOS, all fonts are a sans-serif font (not sure exactly what), but now the dropdown entries in SfComboBox are a Serif font, which stands out badly.
I have tried debugging to see if the control DropDownFontFamily has been set anywhere but in the object inspector DropDownFontFamily = null, which is consistent with all other controls FontFamily property.
So this seems to be something wrong specifically with the SfComboBox. Note: the normal text display of SfComboBox is OK. It is just the dropdown entries that are messed up.