Arrrgh, I get it, sometimes I’m really dumb 
I have a Spline component and Spline Mesh Components added along spline. Spline points was correctly changing their locations, but I didn’t updated Spline Mesh Component position by “Set Start and End” node - so they stood in the same place and I’ve thought that it’s not working.
So, remember kids, after moving spline points while using Spline Mesh Component, always update Spline Mesh Component properties! 
Thanks for help bro!
- Slavq, the dumb IT Engineer