Dog to dog interaction advice!

Hi, every time my dog meets a dog out on a walk, he will happily go up to them, sniff them etc, but as soon as the dog goes to sniff him back he will starts running around, and what looks to be him trying to get away from the other dog. This is not him trying to play as that looks VERY different to this. He’s trying to back off and not let the other dog sniff him back. If the other dog disengages he will happily walk off with me and will often shake as we walk away, yet if the dog doesn’t leave, which unfortunately is the case most of the time, he will continue to do this running around thing until the other dog leaves. If I try to get him to come with me, sometimes he will but the seconds the dog tries to sniff him again he’s doing it all over again. I’m really unsure why this is happening, since on the odd occasion the dog he greets doesn’t want to sniff him/is un interested, he’s happy to interact and hang around them, even sometimes barking to try initiate play. So that’s confusing me. It’s very difficult to handle these situations as dog comes up to us a lot, so it’s hard when he’s constantly spinning around, tripping up etc. does he need more training? Does he need more dog interactions in more controlled settings? Or is this just how he is. Because I don’t see any other dogs doing this 🙁