DeletedUser245 there is a way to disable these pop-up notification globally?
Short answer: it doesn't look like it.
The setting you want is "Pop on screen", which you would have to disable for each individual notification type.
Possible hack: Do Not Disturb mode disables this globally (by default, under Custom restrictions). Maybe you could disable most of the other features of Do Not Disturb mode, but keep this one. Doesn't seem like a great solution to me, but at least worth mentioning.