^^^ Yea they are lying, its an 8ms panel, its a mistake by Qnix, the X-Star is listed correctly (the two are the same monitor just sold by a different company.
Response time makes no difference what so ever. Response time is a measure of how long the pixels take to respond to an incoming signal, it does not mean for example that the monitor has x ms of input lag. Actual input lag is determined by the response time of the pixels plus whatever processing time there is in the scaler of the monitor.
The Qnix is barebones and only has a single input, meaning theres no nothing, it simply takes the signal to the panel, meaning no input lag. I used my old VG278H (2ms response time) next to the Qnix and there is no difference what so ever.
What response time does tell you is how much motion blur a monitor has, but again this is influenced by other factors.