This is just an observation; I don't know if it can be solved...
Even GitHub does not count contributions correctly (but it does better than the stats here).
For example, at this moment GitHub says for me '220 contributions in the last year'. I had much more than that, but GitHub lost their count the moment I changed the commit e-mail (I was wrongly using a company e-mail that had nothing to do with my open-source projects).
Instead of counting the commits for the account, GitHub only considers those that have set a particular e-mail address. Those are not statistics for the account, but for the email.
This is just an observation; I don't know if it can be solved...
Even GitHub does not count contributions correctly (but it does better than the stats here).
For example, at this moment GitHub says for me '220 contributions in the last year'. I had much more than that, but GitHub lost their count the moment I changed the commit e-mail (I was wrongly using a company e-mail that had nothing to do with my open-source projects).
Instead of counting the commits for the account, GitHub only considers those that have set a particular e-mail address. Those are not statistics for the account, but for the email.