Hi @piotr.nowak,
UPDATE: I Changed the demo, and used real column headers (not using letters from the generator) and data. I can confirm that it is now moving the way I expected.
Please recheck the demo. It’s now working. BUT, my problem now, is that it is working in the demo, but inside my real project it is not. Before using v8 beta 2, it was working on V7, but right now it won’t. After I move a column, it will just flicker or flash for 1 second and then revert original position. When I turn off the persistentState, it will work perfectly again. But if I turn on persistentState, the flicker would come back again and will not reposition as expected.
I cannot recreate this issue for I also don’t know what’s going on.