Deleting downloaded tracks from device

Hello everybody

I am about to get the subscription to iTunes Match but before doing it I had a trial period with a friend device (iPhone 6 with iOS 8.1.3) so to see how iTunes Match works.

I immediately noticed a so strange behavior and I would like to ask about.

I tried to play, first, one track in streaming from the cloud and, then, download another track and play it from the device: both worked great!
The proble started when I decided to delete those two tracks from the iPhone: unfortunately I wasnt able to do it even if I was following the Apple support page

https://support.apple.com/it-it/HT202675

I was of course swiping to delete as usual (even tried both way of doing it) but no "delete" message appeared for both tracks while for all the rest of the tracks on the iPhone it was correctly possible to delete them.

I think the support page is wrong and for some reason it is not possible to delete anymore tracks downloaded from the cloud with iTunes match.

Considering the huge amount of tracks and the lack of space on the single device if it is really no possible anymore to delete tracks downloaded, that would be a strong shortstopper. My friend told me that was possible in the past and for some reason it looks like it has dropped as an option.

Can you please be so kind as to help me with this?

Thank you so much in advance

Ciao

Luca