Getting device names ... fails?

Hi again,

I want my puck to wait a little longer before going into code that changes its name and advertising behaviour. But want it to wait only if a certain device is around (e.g. my iPhone).
So I tried to do a scan or a request ... but this never returns ANY names of the devices, even with higher timeouts and "active" being true?!
"namePrefix" does not make a difference when using findDevices – it just lists all, regardless of what I set. "namePrefix" does the opposite when using requestDevice – it never finds any, even if I just set one letter. Yes, I can see plenty of devices around using nRF-Connect including the ones I want the Puck to find.
This is what I have tried:

NRF.findDevices(function(devices) { console.log(devices);}, {timeout : 5000, active : true, filters : [{ manufacturerData:{0x004c:{}} }] });

--> puts out a rather large list, but without names

NRF.findDevices(function(devices) { console.log(devices);}, {timeout : 5000, active : true, filter : [{ namePrefix: 'S' }] });

--> shows the same full list without names, although only two devices would fit.

NRF.requestDevice({timeout : 5000, active : true, filters : [{ namePrefix: 'S' }] });

--> times out without any result

I have tried setting timeout to 10 or even 30 seconds – no difference. I must be doing something fundamentally wrong. Please advise.