And a prostick+ i assume?
If you are in Europe, a dark blue SMA filter might fare better.
Actually with that nasty interference near 1066 MHz, i’d personally try a SAW filter:
https://www.amazon.de/AirNav-RadarBox-1090-ADS-B-Filter/dp/B082WR1SDF
There are other makes.
SAW filters have sharper cutoffs and a narrower bandpass than the LC filters from flightaware.
(and the dark blue FA filter is much narrower than the very wide light blue FA filter)