I had the same problem
I had the same problem until I bought a higher quality converter..... I'm a bargain hunter, and I buy a lot if Chinese products to save a Buck, but I have wasted my money on a couple of HDMI converters. The connections are so precisely manufactured that a lot of the cheaper Chinese manufacturing can't make the quality connectors successfully. Buy the higher quality ones and you'll see the difference. If you did buy the higher quality one, make sure the port is clear of debris.... blow it out, look for dirt, grit, etc.