Also while this antenna says it is optimized for 1090 MHz, that is not necessarily the case.
I had a similar one and just replacing the coiled whip with a 6.6 cm piece of wire like shown in the last picture of the previous post helped a lot.
And yes get a food can like the one pictured and place the antenna upon it it helps a ton.
If you don’t have FA ProStick Plus, then that is always a good upgrade.
Buying some good coax and building a Quick Spider is probably the next thing you can try: QUICK SPIDER - No Soldering, No Connector
That is assuming you don’t want to spend the money for an FA antenna?
And yes placing any antenna outdoors as high as possible is always good for reception.
You might want to check your terrain around you, so you know your limits: What is the Maximum Range I can Get?