I haven't had these issues using BT with several BT TWS sets and headphones or DAC/amps. I admit I don't go into open fields very often. I live in a downtown city (about 600K population) where there can be significant foot traffic and a lot of BT devices being used. I also live in a twenty story apartment building. I've used BT TWS in gyms.
Sounds to me you more have an issue with your phone. My initial thought would be radio interference, which may be part of the issue you have. I also think that maybe your phone case may be blocking the BT signal. You may want to see if there is a difference without the phone case on.
There only issue I have come across is BT disconnects from my phone when I go up the elevator in my apartment building. This occurs on every signal BT headphone/earbud I use. And it's only with phone calls. It will do it if I walk by the elevator taking the trash to the trash shoot/room. Some devices do better with this than others. I'm always using TWS outside, at work, and travelling. My previous TWS were always using LDAC or Aptx. The current set using SSC (they're galaxy buds pro 2 with an S23 Ultra).
Sounds to me you more have an issue with your phone. My initial thought would be radio interference, which may be part of the issue you have. I also think that maybe your phone case may be blocking the BT signal. You may want to see if there is a difference without the phone case on.
There only issue I have come across is BT disconnects from my phone when I go up the elevator in my apartment building. This occurs on every signal BT headphone/earbud I use. And it's only with phone calls. It will do it if I walk by the elevator taking the trash to the trash shoot/room. Some devices do better with this than others. I'm always using TWS outside, at work, and travelling. My previous TWS were always using LDAC or Aptx. The current set using SSC (they're galaxy buds pro 2 with an S23 Ultra).