I used to sync them up. But one day you'll have low flow for a few minutes and they get out of sync and it doesn't matter, or you'll step on one, or whatever. I have a different brand, but concept should be the same.
When I have problems with the pool (or anything else), before figuring it out, I usually look online for the most common problems with the component, and look at those (or just fix them if it's cheap enough to fix, since they will likely fail soon anyway). For the floor system, problems that I've encountered:
1. Garbage in the filter over the floor system would block the flow.
2. Low flow: third party filters sometimes had lower flow than the OEM ones, low flow = heads not happy
How old is the system? Mind has a "rebuild kit" that replaced a whole bunch of the parts. Apparently over time they just got worn and it stopped really working by zone. I did the rebuild kit, and it was like brand new. However, problems 1/2 cropped up and make the heads not work, cleaning the filter before the floor system and making sure enough flow in general and system is like new.
If you get it working right, the floor systems are a thing of beauty.