One of the earbuds flashing blue really fast comparing to regular flashing during pairing mode

Hello there,

I purchased earfun air pro 3  two months ago.  Initially, the performance was top notch. But lately I was facing problems with it.  The earbuds while putting on the case and after closing the lid won't turn off. Tried hard resetting it once, but the problem still persisted. 

Now, after doing a hard reset, one of the earbud is flashing blue light really fast, compared to normal flashing while in pairing mode and won't pair with the phone.  While i tried to pair with my phone but only one earbud gets paired, but the other one doesn't pair and flashes blue light really fast.

What is the significance of this blue light flashing really fast? How to solve it?