@nazmibojan your radio IC may be toast by now, so you may have to replace it.
@longjohn119 thank you for the detailed report. My own knowledge about antennas is very basic.
It's definitely much noisier around here in suburban Seattle.
Also always interested how the receivers compare to SDRs, as basically it's a very specialized SDR. For a fairer comparison, you could try to add a bandpass filter in front of the SDRs. My 1-channel dAISy has a discrete LC filter built from SMT components, and it holds up surprisingly well to the SAW filter used on other models. In real world tests the advantage of the SAW was maybe 10% more messages.
An external filtered preamp can help. I observed better range when adding this one in front of the HAT: https://store.uputronics.com/index.php?route=product/product&product_id=93
Adding a preamp on-board is still on my to-do list. I did early experiments which resulted in worse reception. However by now I know that the small dAISy is limited by noise from the USB side. I may give it a try with the HAT, which despite the integrated splitter performs as good as the single-channel dAISy, i.e. the design likely has a lower noise floor.