North Korean troops moved south simultaneously across the MDL last week

I wonder why they keep moving south like this recently.
They say it happened 17 times last year, so it can't be a mistake.
It's been nearly two years since North Korean troops gained actual combat experience in Ukraine.
The US military might be the concern, but they likely view the South Korean military as a given.
In particular, they seem to be gaining real experience in drone warfare; I hope the South Korean military prepares properly.