I am on latest weekly build of xiaomi.eu (7.2.9) on a 128GB Mi5.
I was under the impression that the Mi5 didn't use the AptX codec as it isn't a listed device, but I connected my AptX Low-Latency BT headphones (Plantronics Backbeat Pro) and saw this in logcat:
i.imgur. com/EAeMrZc.jpg...