On Ubuntu 22.04 LTS: Mesa driver version is 22.2.5: `Webrender` is used by default, the problem is reproduced. On Ubuntu 20.04 LTS: Mesa driver version is 21.2.6: 'Webrender(software)' is used by default instead of `Webrender`, the problem is not reproduced. So, the problem seems to be caused by Mesa driver version 22.2.5.
Bug 1815481 Comment 4 Edit History
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On Ubuntu 22.04 LTS: Mesa driver version is 22.2.5: `Webrender` is used by default, the problem is reproduced. On Ubuntu 20.04 LTS: Mesa driver version is 21.2.6: `Webrender(software)` is used by default instead of `Webrender`, the problem is not reproduced. So, the problem seems to be caused by Mesa driver version 22.2.5.