I understand your situation, and I’m here to assist you through this issue. While we delve into the matter further, allow me to provide you with steps to revert to a previous version of Sketch.
How to Rollback to a Previous Sketch Version
Visit our releases page at Sketch Releases to select the specific Mac App version you wish to install.
Locate the preferred Mac App version and click on the corresponding download link.
If the downloaded file is automatically unzipped by Safari, double-clicking the app bundle will launch the app without installing it.
If need it, move the app file to the /Applications folder.
When macOS prompts that there’s another app already named “Sketch,” opt to “Replace” it.
Please let me know if you encounter any difficulties.
In the meantime, I will investigate this report further.