Half lives aren´t consistent? What next?!

I can´t help but wonder if science just now discovered this, what else do we still not know or have a wrong theory about?

Purdue nuclear engineer Jere Jenkins, while measuring the decay rate of manganese-54, a short-lived isotope used in medical diagnostics, noticed that the rate dropped slightly during the flare, a decrease that started about a day and a half before the flare.

The strange case of solar flares and radioactive elements