I got both 199 and 139 from aliexpress and never had problems. I don't use it anymore, I gave it away for my other family members to use and they never had problems
I've had the aj199 for a bit longer than a year now, so I had one of the early models before most of the yt reviews came out, but I also had some issues with the battery, mainly that whenever the charge falls below ~60% there tend to be small skips in the tracking where sometimes the mouse doesn't track for like a second but charging it once every week so I'm mostly above that charge fixes it to me
