APP Name: System overall and any app/game with Multi-Touch function. Rooted: No Frequency of Occurrence: Always. Firmware/APP Version: Every. RAM: 4G Model: ZE620KL
I bought the 5Z near it's release date in my country and the Multi-Touch problem is here since the first day.
It's like the touch panel don't have full Multi-Touch support, as seen in the MULTITOUCH TESTER app:
When you move one finger on screen it moves as expected, smooth (good, not great anyway).
When you try the same but with another finger holding on screen, movement gets sluggish compared to doing the same with one finger. The moving one gains a delay of almost a second. If you do it, but slightly sliding the moving one, you'll see the "low FPS" effect. (Funny that it doesn't happens with one nor even with three fingers or more, I should call it...Two-Touch issue?)
It breaks any smooth gaming experience that the rest of the hardware have to offer.
There is no specific firmware, app or game nor any specific version of those. It's happening since ever, everywhere.
In THIS VIDEO you can compare the gaming experience between ZenFone 5 and 5Z. If it's the same touch panel, there's something wrong, huh?
In THIS VIDEO you can see (fullscreen) that the aiming and the camera movement in First-Person or Third-Person games are being harmed by the issue.
You can find OLDER and UNSOLVED POSTS about it over ZenTalk.
Please, calibrate it or just tell us if it's a hardware "gimmick".