Bluetooth MP3 compatibity

I've found that my old iPod nano isn't supported via the infotainment head unit. Probably obsolete no doubt as it ran on Bluetooth 4.0, and doesn't want to work via USB either.

I've searched in the Skoda manual for what the minimum Bluetooth acceptability criteria is for media devices, but can't seem to find anything. Also checked in the Search facility on here too but nothing obvious leapt out either.

It transpires that most players appear to be uni-directional so boasting v5.2 makes no difference as they wont connect to a vehicle system. I've located one, on a very short list, which should connect (multi-directional) but is only Bluetooth v4.1.

Can anyone help me with the information I need please?