It is most likely an issue with the antenna. I've had this issue before and had to buy another antenna.
This is what I bought since the antenna messed up. It has been working great ever since I've bought it.
https://www.amazon.com/1091-BNC-Scanner-Antenna-BNC-Male-Connector/dp/B01DY8FTR8
https://www.amazon.com/SMA-UHF-Connectors-Nickel-Plated-Converter/dp/B01MQNJVMT
It is fine if your SDR suddenly disconnects. Just find a place for it to sit and it won't disconnect or even better, get a USB 2.0 USB extension cable.
I use SDRTrunk to monitor Hawaii's PACMERS TRS LMR System.