CoreText garbles ligatures

Snapshot 134, macligatures is enabled. The font I am using is PragmataPro. It's hard to describe what I am experiencing, so let's have a look at two gifs.

Here is entering !== without CoreText:

As you can see, everything looks fine. Here is the same with CoreText enabled:

As you can see, something is quite off here. The ligature gets broken somehow during working on the line. However, when changing the line, everything looks normal. Obviously, disabling CoreText is a perfect workaround, but since scrolling performance is somewhat horrible, I'd love to know if there is anything anyone can do here to resolve this rendering weirdness.

首先，在启用 CoreText 和 macligatures 的情况下使用 PragmataPro 输入 !==，重现该问题；然后比较禁用 CoreText 时的行为。完成标准是：编辑和滚动时连字仍能正确渲染，且滚动性能没有下降。