Application invisible to system and apps

Hello I face problem, that this application is invisble to nearly all applications on my device.
Due to this I can not unblock it in my firewall as it is not listed.

The follwing application can not detect gms-core in any way:

• Afwall+ (root) can not detect the application
• System buildin "apps manager" can not detect the application
• "system app safe remover" (root) can not detect the application
• "lucky patcher" (root) can not see the application

The only application that can see the package is:

• X-Posed based application "quick settings"

I already tried the follwing solutions for testing purposes:

• Install application as user application
• Install application as privledged application
• Signature spoofing enabled/disabled

Additional information:
MicroG package: Services Core com.google.android.gms -> 0.2.4-111-gf1cdb48
Original file: https://microg.org/fdroid/repo/com.google.android.gms-12221403.apk
Device: "Zuk Z2 Pro" / Model: "ZUK Z2121"
Device operating system "OREO (8.0.0)"
OS release: ZUI 3.5.344 ST

Any ideas why this application goes under the radar?
Is this normal?

Start by reproducing the package-visibility issue on the listed ZUK Z2121 device and Android 8.0/ZUI 3.5.344 setup, checking com.google.android.gms with Afwall+, the system apps manager, and the other tools named. Done means identifying why the package is hidden and documenting or fixing visibility so the affected system and root applications can detect it.