TLDR: Climate change is reducing the amount of available food for the bears.
Climate
Discussion of climate, how it is changing, activism around that, the politics, and the energy systems change we need in order to stabilize things.
As a starting point, the burning of fossil fuels, and to a lesser extent deforestation and release of methane are responsible for the warming in recent decades:

How much each change to the atmosphere has warmed the world:

Recommended actions to cut greenhouse gas emissions in the near future:

Anti-science, inactivism, and unsupported conspiracy theories are not ok here.
So... The obvious, unsurprising reason why bears are attacking...
No, you see, the headline says it is strange so you are obviously wrong.
Oh 😔
Clickbait headlines often have dull content behind them it seems.
I'm tired of articles turning into guessing game, those headlines are basically saying "hey guess what's this article is about!". No thank you, I'll pass. News isn't a lottery game.
Its always food, isnt it?
Update: it indeed was food; or put better, the lack thereof for the bears.
Xiao’s study helps fill in the gaps. By analyzing climate and satellite data, Xiao found that a weather anomaly tied to climate change may explain the deadly surge.
The details are complex, but the new paper — as well as a much lengthier, unpublished study that’s currently under peer review — suggests that climate change is weakening winds, known as the westerlies, that bring dry air into Japan and prevent moist air from the Pacific from flooding in. That’s making northern Japan cloudier.
With more clouds, less light reaches the forest. And this is key: Without light, forests fail to produce young shoots, nuts, and other foods that bears rely on, the study argues. That leaves bears hungry and likely to venture into human settlements in search of sustenance. Last year, Akita, the epicenter of bear attacks, “endured one of its darkest springs in recent memory,” the authors write, and beech trees in northern Japan produced almost no nuts.