I quoted from a similar question on solar minima and maxima. "...I guess the jury is still out, but this is quite "fringe" material. The solar cycle is certainly thought to be a product of the dynamo mechanism that produces the magnetic field." So has something changed in the dynamo mechanism?
The solar cycle is no less predictable than it has ever been.
The sun shows a roughly 11 year cycle of activity, but the activity and length in each cycle is also variable and shows trends, but no apparent periodicty
CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=969067
The graph shows 400 years of solar activity. The 11 year cycle is clear, and you can also see some trends in the longer term. The longer term trends don't follow a simple pattern.
So the pattern of solar activity is just as predictable or unpredictable as it has ever been. There is a cycle of 11 years, but what is less clear from the graph is that the some of these cycles are a little longer and some are a little shorter than 11 years. There are longer-term trends that are non-periodic. The causes of the cycle are the periodic relaxations and reversals of the sun's magnetic field. The causes of the longer-term variations are not well understood, and consequently not easy to predict.
There is some evidence of longer-term patterns that are indirectly observable in, for example, variations in the production of Carbon 14 in the atmosphere. There are proposals for periodicities of 210, 2400 and 6000 years.
We can say, with reasonable confidence that the next solar maximum will be in 2025. We expect that the intensity will be similar to the last peak with sunspot numbers at about 100 (based mainly on the observation that there isn't very large swings between one peak and the next). But it could reasonably be between 50 and 150. We would expect there to be peaks in 2036 and 2047, but we have little confidence in how active these future peaks might be, and we are not that confident in the timing.
The cause must be "something in the dynamo mechanism", but such variation is normal for our sun, it seems.