There is a forum section at: https://eyetvforum.com/index.php?/forum/42-beta-software-code-as-it-is/ where people have been reporting numerous shortcomings and bug with EyeTV4 Beta Builds and the release versions for about a year. There is at least one person who does answer feedback there. Unfortunately, it seems that Geniatech have a very small development team [maybe only one person, but I'm guessing], and so fixes for bugs are only7 happening slowly.
The released and paid for versions have so far contained most of the bugs and faults of the Beta builds.
The attitude of Geniatech towards their customers who run Apple hardware has been well below the standard expected by Mac users. They did not even begin Beta testing of EyeTV 4 until after Apple dropped 32-bit support, over a year ago, and despite Apple announcing publicly, and several years in advance, that support would be discontinued.
I have not yet upgraded my operating system because having to use EyeTV 3, which will not work in Mojave, and which has features which are not available in EyeTV 4. A number of other people are having to do the same thing. If there was another reliable 64-bit application which could fulfil the rôle of EyeTV 3, many people would have stopped using Geniatech software long ago.