Android device not found by Unity... at all

Hello! I am just learning unity, and everything seems to be going wall apart from the building and running scene in VR. When it comes to this, Unity states that there is no android device found to build and run scene on. Unity remote on phone doesn't work as well.
System: Windows 8.1

VR device for development: Google Cardboard
Phone: Xiaomi Redmi Note 7, Android 9
Android Studio: 3.6.3 with modules:
- android SDK build-tools

• NDK (side-by-side)

• Android Emulator

• Android SDK Platform-tools

• Google USB Driver

• Android SDK (obsolete) SDK Platforms on for Android 9 and 10.

Unity: 2019.3.12f1 Android SDK+NDK+OpenJDK installed.

USB debugging on device is on.
Device is recognized on PC.

Therefore, I have no idea why my phone is not found by Unity. I am a bit frustrated, because I have to deliver a project till a deadline (I am doing the course for Unity), but due to this issue can't complete it.
Would be extremely grateful for any help!