Single-line TextArea is badly adjusted

I am trying to use a single-line edit field with Styled abilities (in order to apply color to parts of the shown text).

In Carbon, this worked just fine. But in Cocoa, the text gets aligned too high.

See here:

The top field is a TextArea, the lower is a TextField.

While the upper looks wrong, the lower looks well aligned.

How can I fix the alignment for the upper TextArea?

Set TextAreas LineSpacing to 1.15
Whats weird, if you enable Multiline, it breaks automatic if text width > control width. How to enable it to make it look like a TextField?

Changing LineSpacing has no effect in my tests. Trying with Xojo 2017r2.1 - oh, it works in the running app, it’s just not showing the change in the IDE. Okay, so that solves this thing.

Also, even if Multiline is off, pressing the Return key inserts a newline. This doesn’t seem right to me.

Oh great - it works with setting LineSpacing in a simple test project but not in Arbed, where it’s a subclass of a subclass. Sigh. Well, Arbed is not meant to be pretty.