This bug seems to still be a problem: Button font size changes vertical alignment · Issue #778 · thunkable/thunkable-issues · GitHub.
I notice it when I use a smaller font size in a smaller button. For example, 12 point default font in a button that is 30 pixels high. The browser preview looks fine but live testing in Thunkable Live on an iPhone 13 Pro shows the button text aligned vertically to the top of the button.
The problem becomes less obvious as the button size grows and the text size grows. So a 24 point font won’t have that issue. And a 200 pixel button will have off-centered text but it’s less noticeable.
In the screenshots below, see the white button at the top-left of the screen with text “test”.
Design tab:
Thunkable Live:
