Hi,
I have the nothing phone (3) since a couple of weeks and I always had issues with audio stuttering with Bluetooth earbuds. When walking or running with my phone in my pocket I could barely have pleasure listening to music since it was always stuttering. I had to take the phone in my hand or place it somewhere near my earbuds. Like in my coat upper pocket or in a running hydration vest.
I've come to a point where I was going to send it back for refund since I still had 1 week left.
I finally found that if you go into developer mode, under Bluetooth settings and you change the AVRCP from 1.6 (default) to 1.4 everything becomes stable, no more stuttering.
For reference I used LDAC and I had the issue with multiple earbuds, I tried OnePlus Buds 3, Soundpeats Air5Pro + and now with the best for me the Huawei Freebuds Pro 5.
Let's Rock & Run !