>>105669440
>>105678477
Usually the problem is grease and dirt collecting on the contacts, that are usually tiny and hard to reach. It's like they don't test for this sort of thing, a very common problem and people throw away good buds because don't know better.
If you use any TWS buds you should invest in one of these, they're cheap and nice, and some isopropyl alcohol, to clean the electric contacts from time to time