Navigation Block: padding issue in nested submenu when "Open on click" is enabled

[shrivastavanolo]

Description

The horizontal padding for nested submenu items in the navigation block is inconsistent when "Open on click" option is enabled for the navigation block.

How the padding is expected to be:

---

How it is currently:

Step-by-step reproduction instructions

1. Add navigation block to a post
2. Add a submenu block to the menu
3. Within that submenu, add a nested submenu
4. Enable Open on click via the sidebar settings
5. Save the post and check on front end
6. Verify the padding issue in the nested submenu

Environment info

• WordPress: 6.9-alpha-60301
• PHP: 8.2.28
• Server: Apache/2.4.62 (Debian)
• Database: mysqli (Server: 11.8.2-MariaDB-ubu2404 / Client: mysqlnd 8.2.28)
• Browser: Chrome 137.0.0.0
• OS: macOS
• Theme: Twenty Twenty-Five 1.2
• MU Plugins: None activated
• Plugins:
  • Gutenberg 21.0.0
  • Test Reports 1.2.0

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

• [x] Yes

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

• [x] Yes

Please confirm which theme type you used for testing.

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

[R1shabh-Gupta]

Reproduction Report

Description

This report validates whether the issue can be reproduced.

Environment

• WordPress: 6.9-alpha-60318
• PHP: 8.2.28
• Server: Apache/2.4.62 (Debian)
• Database: mysqli (Server: 11.8.2-MariaDB-ubu2404 / Client: mysqlnd 8.2.28)
• Browser: Chrome 137.0.0.0
• OS: macOS
• Theme: Twenty Twenty-Five 1.2
• MU Plugins:
  • Gutenberg Test Plugin, Disable Login Autofocus
  • Gutenberg Test Plugin, Disable Remote Patterns
  • Gutenberg Test Plugin, Enable Templates UI
  • Gutenberg Test Plugin, No-cache Headers
  • Gutenberg Test Plugin, Normalize Theme
  • server-timing.php
• Plugins:
  • Gutenberg 21.0.0
  • Test Reports 1.2.0

Actual Results

1. ✅ Error condition occurs (reproduced).

Supplemental Artifacts