Tiled Gallery keeps resizing in a loop inside Row/Stack in block editor

[Babylon1999]

Description

When a Jetpack Tiled Gallery block is placed inside a Row or Stack block in the post editor, the gallery continuously grows/shrinks (infinite resize loop) and becomes difficult to edit.

How to reproduce

1. Create a new post/page in the block editor.
2. Add a Row block (also reproducible with Stack).
3. Inside it, insert a Jetpack Tiled Gallery block.
4. Add several images.

2026-06-11.21-36-30.mov

Environment

• Jetpack: 15.9
• WordPress: 7.0