I have been testing with various bluetooth earbuds (TWS) to see which are most reliable.
I get frequent Bluetooth 'Interference' with some, leading to some other consequences, detailed below. I tested by moving out of range and back in again.
Sony WF-C700N (Bluetooth 5.2, SBC, AAC)
Generally these perform the best, after interference they recover correctly. Cut-outs are the least of any buds tested, but do occur.
Earfun Free Pro 3 (Bluetooth 5.3, AptX Apaptive)
A huge amount of cut-outs occur in general use. After the range test recovery is very poor, often leading to music being out of sync between left & right ears. Sometimes the music stops in one ear. Just pausing the music can cause one ear to stop playing. Turning bluetooth off & on is required to recover. The buds run as AptX on the M1S.
Cambridge Audio Melomania M100 (Bluetooth 5.3, AptX Adaptive)
Very similar results to the Earfun, except they often just disconnect instead of recovering.
Jabra Elite 3 (Bluetooth 5.2, AptX)
Recover better that the Earfun, but occasionally get out of sync. But a pause & play is all that is required to recover.
It should be noted, that all of these earbuds perform flawlessly with an Android phone. Also tested with a Shanling M2S, which also performs about 95% better with bluetooth.
I used the Earfun buds for an hour while using the lawnmower with my old M2S player, and it worked fine.
I tried the same with the M2S, device in same location, screen facing out. It constantly cut out and was unusable. Even with the Sony buds it was not very good.
As I like to use Bluetooth earbuds, I have concluded that the M1S is going to be unusable for me now, only the Sony buds work to any level of acceptability.
It is very disapointing as I really liked the M2S, so that I thought I would upgrade to M1S. I have had the M1S for 4 months now, so no chance of a return. I like the interface and using the device, but it does not perform.
@Shanling is there any hope of getting the bluetooth fixed? Or should I start looking for an alternative DAP?