I've been working on a Unifi installation in France and the way I generally do things is to work with local electricians so that they do the cable runs and I do the rest. I always specify Cat6 or Cat6A U/FTP cable and I've never had a problem before.
This time, one of the cable runs has been done using this and I've never seen anything like it. It's really bizarre
Three pairs (orange, blue, green) have cores with an insulation diameter of 1.00mm and are bundled together in one foil screen. The brown pair is in a separate foil screen and has an insulation diameter of 1.30mm. The conductor diameter is greater too.
The overall cable sheath is oval.
We ended up with this cable from the electrical wholesaler because the previous cable (of more usual construction) had all eight cores of 1.30mm diameter and it won't fit the RJ45 plugs I have. It needs to in order to plug into the rear of Unifi in wall access points comme ça.