Lots of various call issues and quality with S21

[Prluksha]

I have an S21 with a Samsung flip case.

Ever since I've gotten this phone I've had the following issues:

- People complain the audio quality is horrible coming from my phone. It's distorted, choppy, and drops a lot.
- Whenever I put the call on speakerphone the person on the other end can hear themselves. This also sometimes happens with speakerphone off if I have the volume up.
- Occasionally I can't hear the person on the other end at all, or only for a few seconds. This also happens the other way around where the person on the other end hears me for a few seconds, but then can't hear me anymore. Usually calling back fixes the issue.

These things happen regardless of if I only have a little bit of service, full bars of 5G, or really strong wifi signal.
It's been happening for at least 2 years now and getting to the point where people at my workplace hate calling me because of these issues, and it makes phone support nearly impossible. If anyone has any ideas, I'm open to try anything.

[Piper123]

The S21 Ultra Exynos version is widely reported to be a poor device with a poor modem. I had two of them and sent them both back for refund.

Unless you are in a city or large town with a mast in your back garden, S21 Ultra will disappoint in terms of connectivity to your network carrier, regardless of which one you use sadly.

[Members_vz88Jcd]

I cannot believe how bad this phone is at making calls. After 25 years with Samsung, I am finished with their phones.