canvas display anomalies

[wangyuks]

Describe the bug
A clear and concise description of what the bug is.

To Reproduce
Steps to reproduce the behavior:

1. connet vnc success
2. canvas display anomalies，Sometimes it can't be displayed, sometimes a small box is displayed, and the input content is too laggy

Screenshots

[wangyuks]

The interface looks like there is data returned, but the page is not rendered. Occasionally rendering normally, but unable to input content

[CendioOssman]

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