nRF Connect - Only a few devices listed in Android

We as a company love the app (nRF Connect) and use it accross a lot of devices to recover stolen goods with BLE.

However, on all my Android devices (modern tablets and phones on different of modern Android versions) the app only shows 3 devices while a lot of other apps show 9 to 16 devices.

How come?! I played with the settings, but whats wrong, or what are we doing wrong?

The iPhones with nRF Connect all work amazingly well and also list loads of BLE devices.  

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