The problem is that the viewport size is the scaled size based on the device scale factor, but when only scale factor changes, we don't update the viewport size.
Pull request: https://github.com/WebKit/WebKit/pull/15925
Committed 266157@main (690223fa5be1): <https://commits.webkit.org/266157@main> Reviewed commits have been landed. Closing PR #15925 and removing active labels.