oh man, I've used a wrong tag, it should be "Safari Extensions", not system, can some admin change that?

Hello @arnoudkooi, Did you managed to find a solution for this? I'm trying to solve this for a whole day now. When I send a message with browser.tabs.sendMessage to a tab that I've created it won't receive it at all. No matter if I send it from a different tab or from a background script. It will receive messages send through the browser.runtime.sendMessage though. It feels impossible. I've tried also chrome namespace but with the same results. Is everyone else using browser.tabs.connect API?