I wouldn’t call that working fine and the wire you stuck in was too long, should be 6.8cm 
Anyway to me it looked like the antenna is working fine, it just picks up strong noise that overloads the amplifier or receiver in the blue dongle.
You could do a scan for noise like described here:
(Do I Need A Filter?)
For that just connect the blue dongle to the antenna how it is installed.
Use a gain of 35 for the spectrum scan.
As for filters there are multiple available.
The round blue filter sold by FA is one option.
Or you can try one from Hong Kong, this one for example:
(https://www.ebay.de/itm/1090MHz-ADS-B-Passive-Bandpass-Filter-BPF-Software-Radio-Software-Radio-SDR/253735059773)
No guarantees, if the filter does what it says it is good but you never know on ebay
Best filter in my opinion is this:
(New Product: RTL-SDR Blog 1090 MHz ADS-B LNA)
But you need a bias-t to use it, so you need additional stuff.