earfun air pro 4 crackling

Apparently this is happening to other people when I do a search online. I've had version 3 for a couple of years and decided to upgrade to version 4. The sound, ANC and everything was much better and I really enjoyed the earbuds for a day or so. Now the right earbud will crackle whenever ANC or Ambiant mode is on. This started when I first used them in my office today and connected them to my macbook. I thought it may be interference with something so I disconnected my laptop, turned of laptop bluetooth and put laptop to sleep etc. and removed my laptop from the list of devices in the earfun app. But the crackling still happens and it will now happen anywhere in my house. It was all working fine yesterday for many hours so there shouldn't be any new interference in the other areas of my house. I never had any problems with version 3. Is this something that is fixable with new firmware or should I return my version 4?