Strange behavior when switching bold and oblique styles

[ShikyC]

Hi community, I just created an OTF file with 4 styles of my font: regular, bold, oblique and bold-oblique. I also set the flag for macStyle and fsSelection as follows:

Style	macStyle	fsSelection
Regular	0	64
Bold	1	32
Oblique	2	1
Bold Oblique	1|2	32|1

And the TTCollection are created by appending the 4 TTFont objects in this order: regular, bold, oblique, bold-oblique.

However, the output font's style switching behavior is glitchy; First, in my FontBook (macOS) app, the Bold style seems to be set as the default style; Then in the text processor app (Pages), if I toggle the B button, there's nothing happening; If I toggle the I button, the font switches between Bold-Oblique and the previous styles, like this:

Screen.Recording.2023-10-12.at.12.11.43.PM.mov

I guess I must have missed some properties settings when creating the font collection. Can somebody help me find out?

[ShikyC]

Problem solved by setting the correct usWeightClass values in the OS2 table.