@Robert_Zwetsloot I’m still here, reading along!
As far as I know, most of the questions asked are already answered many times before and most solutions are known by the community, or don’t need my assistance. Many other problems are just configuration issues (e.g. wrong ip-address) or issues with external platforms (HA, NodeRed, etc.). Ofcourse I know some problems with the app are left unsolved and feature requests remain open.
E.g. the connection issue; this is a known problem with the socket connection between Homey apps. It can be solved by restarting the MQTT Client & Hub apps in that particular order.
The MQTT Hub isn’t the only app with this particular issue: [App] Tasmota MQTT - #265 by Joka. Yes it’s annoying…
Maybe I mised something, but where is your contribution? Feel free to provided solutions to any remaining issues. The source is open and I’m willing to assist with pull requests.
The thing is: I migrated my complete setup to HA about two years ago and therefore the MQTT Hub is low priority. Nowadays my Homey is just an expensive football, so it’s much harder to test and answer questions and there is no personal benefit in any way. Although there is no active development from my side, the project is not abandoned. I’ll be here if things fall apart 
!
I just hope many people enjoy the work put into this project!
