If you connect the headphones with the jack cable, do they also stutter?
If not, it's the Bluetooth, I would recommend "throwing out" the headphones again in the mobile phone settings and reconnecting them from scratch.
If that doesn't help either, I would check the headphones app to see if there is an update (I don't remember if you can update it)
If nothing helps, it may be your mobile.
Try connecting it to another Bluetooth device.
If it does not stutter here, then reset your mobile 🤷‍♂️
(don't forget to make a backup)