Greetings Music Addict,
I was able to fix my old set of Pixel Bud A series and get an additional years worth of life out of them when this happened to me by simply using some electrical shrink tubing around the affected area. I purchased mine at the local harbor freight and have been using the stuff for years. I don't know exactly where yours are splitting by for me it was on the side so it fixed them right up.
[link|https://www.harborfreight.com/127-piece-heat-shrink-tubing-set-67524.html?utm_source=google&utm_medium=cpc&utm_campaign=12169054043&campaignid=12169054043&utm_content=125548918068&adsetid=125548918068&product=67524&store=3222&gad_source=1&gclid=Cj0KCQjw_qexBhCoARIsAFgBletHk58ikfKlvsmaBduH4v2c7vBsIYbqQvB_xwSSmR3WLSuCbdw0YzAaAu0yEALw_wcB|Multi Size Shrink Tubing|new_window=true]
I hope this helps.
Moe