The activity score seems to be stuck

Sometimes after a day at Lingq my activity score seems to be stuck somehow. It is the score at ‘all languages’ and ‘all countries’ that seems
to get stuck, for as I add all individual language scores, they add up to
a different amount than the total at ‘all languages’ and ‘all countries’.
Do you have any idea what is happening?

And now it is unstuck again… to me it is all a mystery…