Troubleshooting

Try first

Ensure adb devices shows your device
Ensure adb shell opens a working shell on your device
Try running frida-server through an ADB shell
Ensure Magisk is at a STABLE version and up-to-date
Ensure MagiskHide is disabled
Ensure you are on an AOSP-based ROM

Not solved?

Please open an issue and post detailed information about your device (including logs!)