Migs have parts that need replacement periodically. The torch liner in the hose is a typical cause of what you describe on many brands. Either made of tightly coiled wire or plastic tubing depending.

If the welder did not do this when newer it is typical cause. It is sold separately as a part. If it did it from brand new the actual wire drive unit is either not adjusted properly or is as you mention perhaps of questionable quality. I also guess you might be feeding wire too fast. It jamming into the work and creating back pressure on the wire. But I suspect you would see this happening.