Hi,
usually the outputs should by synced.
There are two things you should check.
All four outputs need to have the same timing. Even if you don't use all outputs, make sure they all have the same setting. There is an option saying ` copy output one as default` or something like that.
If the outputs are set up correctly, the four coloured boxes should turn from red to green.
Next thing is that the input timing needs to have at least the same frame rate like the output does have... If so, also the coloured box here will turn green.
If input rate does not match the output rate, there will be frames dropped or frames shown twice, that's what my explanation looks like

.
We used the x4 sometimes with ultra narrow displays or with softedge projections.
We will do some more detailed and precisely measurements in the future, also to verify the delay and stuff like that as we do have quite a lot of them.
Cheers,
Tobi