: If you use a laptop with both integrated and discrete graphics, use the Windows Graphics Settings to force Slack to run on the High Performance GPU or Power Saving GPU to see if one stabilizes it. Troubleshoot connection issues - Slack

Windows 11 has a built-in repair feature that is more robust than the old "Uninstall/Reinstall" method.

If Slack freezes before you can reach Preferences:

Start with Step 1.