Hello,
I’m using Samsung Galaxy S9+ (exynos, android 8) and last night I rooted it in order to convert an app to a system app using Magisk(https://www.youtube.com/watch?v=uYYyxWH3xew) .
I had troubles opening Magisk manager until I turned the internet off. Converted an app to a system one and then removed root through magisk manager (complete removal button).
I spotted that google play and other google apps are missing. Google play services are missing too, means I had to install other apps by downloading .apk files. Google play services (for AR+) are causing me headaches as one app which uses that keeps crashing.
Question: Do I have to unroot using TWRP or what? Every help is welcome 
Thanks!