Thank you for your reply.
I purchased my Formuler Z12 Ultra from the official Amazon store. When I received it, MyTVOnline 3 was not installed and it was not even available for download in the App Store. After several updates, I was finally able to install it.
The version I am currently running is MyTVOnline 3 v12.1.36-5048-994217d35.
I have already tried clearing the cache, performing factory resets, and setting up the device from scratch multiple times, but the problem remains exactly the same.
The issue only occurs when I perform rapid channel zapping through multiple channels. After switching quickly between channels, the box eventually freezes and no channels will play until I reboot the device. If I change channels slowly and allow each channel a few seconds to load, everything works perfectly without any issues.
At first, I assumed this was a software issue that would be fixed in a future update. That is why I decided not to return the device immediately, especially since Amazon allows returns. However, after several months and without seeing any update that addresses this problem, I am starting to consider returning the Z12 Ultra and continuing to use only my Z11 Pro, which has never shown this behavior under the exact same conditions.
Has Formuler identified this issue, or is there anything else I can test before deciding whether to keep or return the device?
thank you for you answer