Thanks Heiner
I indeed use the wifi.
I tried with a „Avantree DG40S“ BT dongle.
A second controler „max2play“ #1″ is displayed on my devices and both samsung A5 and Note 8 can pair to it.
Unfortunately, they can not connect: both smartphones devices stay in red and in the yellow box displays „Failed to connect: org.bluez.Error.Failed“ (whatever the request is made on the M2P or on the Samsung side)…