I too discovered a couple of weeks ago that a substantial number of my commits weren't showing up on GitHub. After some research, I learned that because I was working on a non-master branch, none of my previous commits that I'd pushed would count even after I merged the branch to master. In the end, the only commit that was added to my GitHub graph was the merge.
So it seems the lesson is, if you want more commits to show on your page, you pretty much need to work entirely on master or merge to your master branch all. the. time.
Edit: The experience was legit, but the 'lesson' is not entirely true. Updated new findings in a later comment.
Huh, that's interesting. Seems like not a good representation of work though.
I agree about it seeming a terrible representation of your work. I've been working around the problem, but I'm pretty dissatisfied with my workflow. So I did some more digging.
And it turns out what I wrote last night was a little inaccurate. It's not the master, but the 'default' that is the only branch that can populate commits onto the graph, but it happens to be that default is set to master. It sounds like you can set the default to another branch to reflect the commits you make there.
It seems a little tedious, but it's a solution. Not sure if commits appear or disappear on your graph though if you're setting your default to something else all the time. Might be worth experimenting with!
By the way, have you figured out yet what the cause has been for you?
I haven't been able to figure it out because it seems like even if I'm working in the default branch the commits may or may not show up on the contribution graph. As long as the commits are showing up in the repo itself I'm not too worried about it, just wish the work was reflected in a better way.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.