My iPhone seems to be burning cables

I’ve been using the original cable of my iPhone since I bought the phone back in 2019, until it stopped charging on one side, then a day after, it stopped charging on either sides. I bought a certified cable and it worked fine for a month until it did the same thing. I’ve checked the cables and the 4th or 5th copper lining of the connector developed some black rings around them. The cables have never been misused or tempered with, especially the new one. I’ve never seen something like this before. Think I should get the phone looked at? I’m not really into the idea of buying a new cable every month.