Chrome on Wayland: having more than one window makes it stutter

If I'm using Chrome (Version 88.0.4324.182 (Official Build) (64-bit)) under Wayland, and I pick a tab, and drag it out of the current window, it correctly creates a new window. But this new window has performance issues, and often freezes for a few seconds while using it. The original window seems to be affected as well, but to a lesser degree, in my experiments. Other windows seem to be unaffected.

I also checked it was not a one-session problem, so I logged-out and back in, tried again, same result.

This behaviour renders Chrome very poorly usable when this happens.

Update:
Closing any additional window, makes Chrome work smoothly again.

The same issue happens when opening a new window from the panel or from the menu, so the issue appears to be about handling more than one window.

Doing the same on X doesn't result in any apparent performance degradation.

Works fine on:
- Chromium (Version 88.0.4324.182 (Official Build) snap (64-bit))
- Firefox (85.0.1 (64-bit))
- Microsoft Edge (Version 90.0.796.0 (Official build) dev (64-bit))

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Affects:
- Chrome Stable: Version 88.0.4324.182 (Official Build) (64-bit)
- Chrome Dev: Version 90.0.4421.5 (Official Build) dev (64-bit)

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: gnome-shell 3.36.4-1ubuntu1~20.04.2
ProcVersionSignature: Ubuntu 5.4.0-65.73-generic 5.4.78
Uname: Linux 5.4.0-65-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.16
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: GNOME
Date: Mon Feb 22 11:24:08 2021
DisplayManager: gdm3
InstallationDate: Installed on 2020-04-03 (324 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Beta amd64 (20200401)
RelatedPackageVersions: mutter-common 3.36.7+git20201123-0.20.04.1
SourcePackage: gnome-shell
UpgradeStatus: No upgrade log present (probably fresh install)
mtime.conffile..etc.apport.crashdb.conf: 2020-09-16T18:33:51.843197