Strange TextBox text alignment

[robkri]

I have a strange behavior of TextBox that I cannot reproduce reliably:
Sometimes the TextBox doesn't center the text vertically. This happens in a windows application I am working on.

But it also happens in the fluent_ui showcase (web):

When I take the code from the showcase example and put it in a separate file, the text is perfectly centered, no matter the height of the TextBox. When starting the showcase as a windows app, the text is also centered.

Any idea why this happens?

[robkri]

It seems to be a bug: #1027