How to set all Google Chrome notifications act like alerts?
Chrome uses its own type of notifications that aren't necessarily system native - my apologies for the extreme vagueness, I don't know how else to put it. This can depend on whether its a website notification that you can get from an update or one related to chrome itself.

What I believe you are trying to do is force chrome to use native notifications throughout. Try this:

In your search bar input this: chrome://flags/#enable-native-notifications. Set this to enable. 

Then, under Setting &gt; Notifications set both the Google Chrome apps to Alerts.

I hope this works.