Constant birds nests on main line help

Main line mono around 0.22mm attached to mono shock leader around 0.30mm, casting weight 50g, casting distance as far as possible around 100m. Quite stiff carp rod 3.9m with big rings, fixed spool reel

Doing lure type of Fishing, so constant casts and retreats.

My problem is that I quite often get those very annoying small birds nests on my main 0.22 line, usually not too far from a shock leader. It's just keeps happening, I have no idea why

Any advice ?