Pretty sure it's this:
5th row down, 1 & 2 are in the same boxes. Forcing 4 into the top middle of the middle middle grid.
I forget the technique that got me there but it's muscle memory intuition from years of doing them.
I also think initially that the top left top left corner has to be a 3.
PM me if I win.
https://youtu.be/VUelKDmaZvMLmk if you can even consider tracking his thought process.