TextInput: first character jumps vertically when font size set via Uniwind className (text-sm) — inline fontSize works

[fendyk]

What happened?

When using Uniwind's text-sm className on a TextInput, the text rendering is vertically misaligned. Typing the first character causes the text to "jump" vertically
inside the input, then it settles into a stable (but still slightly off) position once a second character is typed. The same TextInput styled with an inline style={{
fontSize: 14 }} (the value text-sm resolves to) renders correctly with no jump.

The bug only reproduces when the font size comes from a Uniwind className. Inline style works as expected.

Steps to Reproduce

Steps to Reproduce

1. Clone the repro repo and run npm install.
2. Start the app: npx expo start -c and open in Expo Go (or a dev build).
3. Tap the first input (Uniwind text-sm) and type one character — the text visibly jumps vertically.
4. Type a second character — text settles, but baseline still differs from the inline-styled input below.
5. Compare with the second input (inline fontSize: 14) — no jump, correct vertical alignment.

Snack or Repository Link

https://github.com/fendyk/uniwind-textinput-bug

Uniwind version

1.6.2

React Native Version

0.83.4

Platforms

iOS

Expo

Yes

Additional information

• I've searched for similar issues in this repository and found none

[Brentlok]

text-sm sets both font-size and line-height, not only font-size

We're just converting CSS to RN style objects

[Brentlok]

If you set lineHeight to 20px in inline style it's basically the same issue, so it's not related to uniwind

uniwind-textinput-bug.mp4