Very possible that it’s just worse signal now that you removed the groundplane.
Or limited view caused by the roof itself / trees.
Or an issue with solar panel inverter close by causing issues.
It’s really hard to say what the specific issue is.
You stated that the previous install spot on a metal roof was working better.
How far away was that, how high in regards to other buildings?
https://discussions.flightaware.com/t/three-easy-diy-antennas-for-beginners/16348