ViewSonic XG2405 stuttering at 50hz refresh rate

[Hansen79]

I've had this monitor (XG2405) for 3 weeks, it's a very good monitor but i've a strange issue: if i set the refresh rate at 50hz the monitor has pretty bad constant stuttering/microstuttering

It is very evident using the UFO test at 50hz ( https://www.testufo.com/ghosting ): on my XG2405 i get something like this UFO test microstuttering demo: https://www.testufo.com/stutter#test=st ... stuttering

Does somebody who have a XG2405 can test his monitor and tell me if he has the same problem?

Thanks and sorry for poor english