An interesting deal with this from my personal experience (which matches yours)...it was often "contagious"...at least with shooting. If one guy was cold sometimes everyone was, and obviously the opposite if he's hot. Momentum is a fascinating concept in sports. Now I watch team sports on television instead of playing them. Announcers will talk about momentum as if it's a law of physics. It's universally accepted to be "a thing"...but what is that thing?

What's interesting is sometimes it's also not "contagious". And how much of that is placebo? All of it? Probably but any actual thinking about it is usually only at the sub-conscious level. Except sometimes the coach or bench brings it up and then it's not.

The psychology of sports is endlessly fascinating.