It's not just the usual 11-year cycle. As the article explains, the solar shield is weakening so that the maxima and minima of the cycle are lower than they were a few decades ago (see the first graph in the article). This means that more radiation reaches the Earth's own magnetic shield at each point in the cycle compared to the same point in the cycle in previous decades. And that effect will be compounded by the weakening of the Earth's own magnetic field. So for a number of reasons we're all getting higher doses these days.
The article doesn't say anything about why solar activity is weakening. So it seems this could just be a temporary fluctuation. The article's first graph shows that there was a weak cycle peaking around 1970 too, then it got stronger and recently weaker again. Are there studies of longer trends? And is there any understanding of the causes inside the sun? The small window of data shown in the article doesn't seem an adequate basis for prediction beyond the next few years.