Korean characters not rendered after switching from Flash CS4 to Animate

I use "Microsoft YaHei UI" for displaying Chinese/Japanese/Korean characters in my game.

I recently switched from Flash CS4 to Animate, and now Korean characters no longer show (Chinese and Japanese still seem fine).

I've noticed that the number of embedded glyphs are showing less in Animate than in Flash CS4.

In Flash CS4:

In Animate:

So in Flash CS4 it is showing as 62280 and in Animate it is showing only 29079.

Does anyone know why this is happening, and what I may do to fix it?

Thanks in advance.