My stock 2012 did the same thing. It was brand new. With the zip type thing, mine was good for about an hour. A good one will hold all night, and longer, like you are saying. I thought about a rebuild. Master cylinders are really easy to rebuild, but the odds of bad seals in something that new didnt sound like it was worth investing 50.00 in for the kit.
The 2010-2015 /older zx10 used the same master cylinder. That list is long...zx6, versus 1000, etc. Maybe you'll get a good one? If you go to the kawasaki parts breakdown and look at the master cylinder, this master cylinder has been used for a LONG time.
The 2016 and newer zx10 has a nice Brembo master, but it's too small for the stock calipers. Find one from the 2010-2015 if you stay within the Kawasaki family, which is what we have, already.
The 18x19 oem brembo, from a Ducati, will work much better. You can get one of those for 150-200. Ducati used that size on a lot of bikes, before 2012. Figure 2008-2011 era. I'm not sure that's a great option now. It was, in 2013, when they were new. Mines still good, but you cant get a rebuild kit for any of the modern brembo master cylinders. It will pretty much be garbage when/if it fails. The newer stuff with the brembo m50 calipers uses a small master cylinder, like the new zx10, that's not quite matched up to our calipers. Let me know if you find a good, cheap option.