It's worth running a speed test - just Google speed test and you'll get the option to run a quick test where you can see if there really is a speed problem. This is a local connection problem so the first thing is to check your Wi-Fi connection or wired connection. Zoom says my connection is unstable: Unfortunatly this happens from time to time. If that doesn't solve it, check if there are any software updates for your computer. If you're still having problems, try restarting your computer. My app keeps crashing or closing: First of all, do both of the things above.

You'll usually be prompted to update when you open Zoom if there's an update, but it's always worth checking, as some features change between updates. Make sure you're using the latest version of Zoom: There have been a number of Zoom updates recently, the latest version at the time of writing is Zoom 5.9.3, so it's worth checking that you're using the latest version of the app.

Shut down apps you're not using: Zoom and any video application can be demanding on your computer and internet connection, so it's worth shutting down apps you don't need if you're having problems.

Zoom test link