@Bl0ckHe1d Oh I have a lengthy email conversation. Considering that their support system constantly assigns new ticket numbers to the same email thread, it must be chaos in their office.
I've sent them pretty time detailed descriptions what was happening, but do they read it? One time they asked for a software version even though they could read all that info in the previous email. But most of all all they come up with responses like rebooting the hubs, which I already did if they had read my previous emails fully.
Anyway... I purchased my Eve Energy Matter some time in June/July. But I put it use weeks later.
I don't know when exactly but I installed it sometime in August when iOS16 was still in use. The installation process went as usual with Eve stuff, quick and smooth. Of course I heard the "horror" stories from months earlier, but I had no issues. The switch responded quick as every other one. After I put in a couple of HomeKit rules in that same week, I was happy and continued with my own crap.
After a couple of weeks I noticed that some of the other HomeKit rules didn't fire anymore. Rules that made use of an Eve Weather Sensor did not work anymore. When I looked at it, I saw a differences in measured temperature shown in HomeKit and on the device itself. Even the history in the Eve app was more than a week old - very strange.
After days of tracking to problem, rebooting, reseating batteries, emailing to Eve it became apparent that the Eve Weather had trouble connecting with the Thread network. It took weeks to find out that it had to do with the Eve Energy (Matter). Every time I did a reboot of the nearest borderouter (there are 8 HomePod mini's in the house) the Eve Weather did reconnect to a different node; sometimes a different HomePod mini and sometimes a different Eve Energy (older model) much further away. Every time when that was the case, things worked again. But as the Thread network tries to optimise, the Eve Weather would reconnect to the "bad" Eve Energy (matter) again within the hour and rules started to break again.
Then iOS17 came out and possibly a new Eve firmware (3.2.1), I'm not sure which was first. And that made things worse. The Eve Energy (matter) became unresponsive immediately. It only "woke up" for a minute when I looked at it via the Eve app on an iPhone with bluetooth enabled. When bluetooth was disabled the Eve Energy (matter) eventually disappeared from the Thread network listing. And that was kind of permanent. After hours no change.
I even got a replacement from my store last week, same things happend again with that new Eve Energy.
For reference I installed a Eve Energy (HomeKit only model) on the same spot, and that device works fine. All connecting devices like the Eve Weather had no issues anymore. So to me it became clear that Matter has serious issues: iOS17 does something wring and the Eve firmware fails to keep the Thread network up.
So I will not use the Matter device for now. I'd even asked Eve to implement a "upgrade" button to get HomeKit firmware again on Eve Energy devices (or other devices). Especially for those people that have gone through the same s**t after upgrading to Matter.