This looks like a regression of #63260 ("In-between Inserter: can't scroll over it"), which was closed as fixed by #68075 / #68412 in January 2025. We're seeing the same symptom again on WordPress 7.0.1.
When the mouse cursor is positioned in the vertical space between two blocks (paragraphs, headings) where the in-between inserter (blue line + "+" button) appears, scrolling with the mouse wheel gets stuck for several seconds. After one or two successful wheel scrolls with the inserter line visible, scrolling reliably stops responding. Moving the mouse resolves it immediately; otherwise it resolves on its own after a few seconds.
This reproduces in both Firefox and Chromium-based browsers (tested in Vivaldi), so it does not appear to be a browser-specific issue.
We originally investigated this as a suspected Firefox bug before realizing it wasn't browser-specific. A Mozilla engineer (Botond Ballo) dug into it and confirmed the same behavior in Chromium; there's a Firefox Profiler recording captured at the moment scrolling gets stuck, along with more detail, in that thread: https://bugzilla.mozilla.org/show_bug.cgi?id=2054425
Step-by-step reproduction instructions
- Open the block editor on a post with several paragraph/heading blocks (enough content to allow scrolling).
- Move the mouse cursor into the vertical space between two blocks until the in-between inserter (blue line with a "+" button) appears.
- Scroll with a physical mouse wheel while the cursor stays in that space.
- After one or two scroll ticks, scrolling stops responding until the mouse is moved (or a few seconds pass).
Environment info
Please confirm that you have searched existing issues in the repo.
Yes — this appears to be a regression of the closed #63260.
Please confirm that you have tested with all plugins deactivated except Gutenberg.
Not yet confirmed on a clean install; happy to test that if useful for triage.
This looks like a regression of #63260 ("In-between Inserter: can't scroll over it"), which was closed as fixed by #68075 / #68412 in January 2025. We're seeing the same symptom again on WordPress 7.0.1.
When the mouse cursor is positioned in the vertical space between two blocks (paragraphs, headings) where the in-between inserter (blue line + "+" button) appears, scrolling with the mouse wheel gets stuck for several seconds. After one or two successful wheel scrolls with the inserter line visible, scrolling reliably stops responding. Moving the mouse resolves it immediately; otherwise it resolves on its own after a few seconds.
This reproduces in both Firefox and Chromium-based browsers (tested in Vivaldi), so it does not appear to be a browser-specific issue.
We originally investigated this as a suspected Firefox bug before realizing it wasn't browser-specific. A Mozilla engineer (Botond Ballo) dug into it and confirmed the same behavior in Chromium; there's a Firefox Profiler recording captured at the moment scrolling gets stuck, along with more detail, in that thread: https://bugzilla.mozilla.org/show_bug.cgi?id=2054425
Step-by-step reproduction instructions
Environment info
Please confirm that you have searched existing issues in the repo.
Yes — this appears to be a regression of the closed #63260.
Please confirm that you have tested with all plugins deactivated except Gutenberg.
Not yet confirmed on a clean install; happy to test that if useful for triage.