Headphones

Over the past few years, I have bounced from iem to iem. Most of them were around $20, so I just replaced them when something went wrong (and I couldn't fix it or had to buy something to fix it). However, I had a recurring problem after about 2-5 months of daily use. The left channel gets super quiet. This has happened on every single iem I have owned over the past 3 years (except for my er2se which got stolen very quickly after I got them). This happened recently to my Arias, which I do not want to replace ofc.

I have tested the device or dongle, and they are good. However, I do not have a spare cable, so I cannot figure out whether it is the cable or the actual items themselves. I have been storing them in an iem pouch from another fallen iem. I have coiled the cable up every time and have kept it mostly in my pocket. I have also cleaned the nozzles of the iems, and my ears. Should I buy a new cable, or is there something else I could try to fix the problem?