Same Setup/location total different results

@flieger28
Did you try Quick Spider?
It costs pennies, and is easy to make.
It may possibly improve. No harm in trying.

https://discussions.flightaware.com/t/three-easy-diy-antennas-for-beginners/16348/8

The only drawback is that you will need a pigtail or adapter to connect RG6 coax to your Dongle:
F-female to MCX-male for generic DVB-T
F-female to SMA-male for Flightaware ProStick.

F-male to MCX-male Pigtail

.
F-female to SMA-male Pigtail

Your recent upgrade seem to have made significant improvements.
Are you using dump1090 1.15?

The newer FA version seems to get more aircraft, from memory.

Tweaked a little bit further.
1.Red line is starting point.
2.Green is after i put the antenna a bit higer
3.Grey is even higher but a different antenna (has some rust on it)
4. Yellow Maybe 10 cm higher than 3, same antenna like in 1 and 2. And i fixed the antenna only with cable ties, in 3 i uses a metal Plate with a clamp.