So, I had exactly the same issue as everyone else in this thread - only my right earbud worked. However, after reading all the advice, and playing around with the buds for an hour or so, I eventually got the left bud to pair with the right. The "fix" was exactly as posted:
"first unpair the device...then place both earbuds in the case ...remove both earbuds..then hold down buttons on both for 5 seconds...release..then hold for 8 seconds till pink...then re-pair device..both will work..if not repeat..."
As described, it took three tries before the left bud suddenly linked. Now I have great sounds in both ears. I have put the buds back in the charger, removed, played music, and repeated. The left has stayed connected.
I'll wait and see how I get on over the next couple of weeks...