Mine also ended up breaking off. Quite weird, really sudden, one day I was still kiting, a month or so later I unpack the kite and 3 or so valves are broken off, dangling.. This didn't happen after one year but more like after three or four years though. Just about none of my other kites make it that long though, they all start having valve delamination before that. I tried to get the broken (Ozone) valves off with hot water to replace them and ended up giving up. I've taken off and re glued many valves but none were even close to as well attached as these. So overall still very happy with the Ozone this but it does appear that breaking valves should be avoidable. I've also noted a difference between struts and leading edge. ALL valves on leading edge delaminate, and none on the struts. Or the other way round. Doesn't make any sense it seems, maybe just a coincidence, but I appear to always only have issues with the leading edge.
I had the same problem with two of my edges. I contacted Ozone and they reacted very generously. They replaced the broken valves free of cost even if the kites were older than one year. I received very good service from Ozone for this valve issue.
They always say "known issue" - That is just the trick for making you feel comfortable by believing the brand identified the issue and solved it.
I had the same with several brands like North and Airush, and now I just got frustrated with my Ozone V3 Reo (2015). Exact same issue as on your photos. Local dealer says "known issue - bad batch of valves from China...". Heard the same with North, Airush... The truth is, or at least my opinion: It is just random bad luck. Valves are produced somewhere in Asia, often from different manufactures which switch their ingredients from time to time. Quality checks are almost impossible as those valves will always look good when they are new but it is about the chemicals etc. The valves lose their softener through time. Heat can be a factor as well.
But switching the brand is not helping at all, as it might happen with your next brand again. My strategy is having replacement valves in my quiver, and as soon I needed to repair one valve I try to get rid of the kite asap and switch to a newer one. Once one valve gave up you can be sure another one will give up soon. I am very tired of this topic, you wont believe how many sessions got ruined by this issue. Was really asking myself so many times what the trigger can be... storage, temperature, bad air in the car park, compression bags... well,I think simply bad production plus bad luck.