Font picker not reflecting correct size with custom font sizes

[mikemcalister]

Description

When a theme has several custom font sizes declared in theme.json, the global styles UI does not show the right label for the assigned font sizes. When you cycle through the H1-H6 selector, it shows random font sizes in the select label. See video below.

The issue does not affect a theme like 2025 which has the standard S, M, L, XL, XXL font size pattern. But when more font sizes are added to 2025, the issue does show.

Step-by-step reproduction instructions

1. Add several custom font sizes to theme.json (more than 5).
2. Go to Global Styles > Typography > Headings.
3. Toggle back and forth between the H1-H6 selectors and note the label in the font size drop down versus the actual selection.

Screenshots, screen recording, code snippet

CleanShot.2024-11-25.at.13.56.46.mp4

Environment info

WP 6.7.1

Please confirm that you have searched existing issues in the repo.

• Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

• Yes

Please confirm which theme type you used for testing.

• Block
• Classic
• Hybrid (e.g. classic with theme.json)
• Not sure

[carolinan]

Hi
I don't follow. Are you saying that the font size that is the selected font size in the dropdown does not match the font size assigned to that heading level using theme.json elements?

[carolinan]

Nevermind, I had the sound off when watching the video, I understand now.
Please remember that there may be contributors who are not able to see or hear the video.

[SainathPoojary]

Hey @mikemcalister,

Thank you for reporting this issue. I confirm that the bug exists and was able to reproduce it as described.

Environment

• WordPress: 6.8-alpha-59274-src
• PHP: 8.2.25
• Server: nginx/1.27.2
• Database: mysqli (Server: 8.0.40 / Client: mysqlnd 8.2.25)
• Browser: Chrome 131.0.0.0
• OS: macOS
• Theme: Twenty Twenty-Five 1.0
• MU Plugins: None activated

Screen.Recording.2024-11-26.at.9.51.58.AM.mov

[Takshil-Kunadia]

@mikemcalister @carolinan This should now be fixed. Can someone confirm this by testing, else I will pick this up. Thanks! 🙇

[Mamaduka]

This could be a duplicate of #67721. This was resolved by the following PRs: #67733 and #67815.

Can anyone confirm that the issue can be reproduced with Gutenberg 20.0?

[Mamaduka]

@SainathPoojary confirmed that the issue had been resolved.