Test the earbuds on the current host system with no other Bluetooth devices connected and enabled.
If the problems end then enable other Bluetooth devices one at a time (allow time between additions) to discover a possible conflict.
Failing that:
Try the earbuds on another known working system.
If possible try other known working (no choppiness and/or random cutoffs) earbuds on your system.
Determine if the problem follows the earbuds or stays with the current host system.
Overall, my thought is that the earbuds may simply be defective in some manner of design, components, assembly, etc...
Unless the earbuds can be shown to properly work in some functional environment then the earbuds should be returned for a replacement set...