Have a Kato double x-over in which both locomotives stall only when passing through one path or route of the crossover while passage thru the other route or path is flawless. Doesn't matter forward, backward, clockwise, counter clockwise...Running DCC but same behavior occurs on DC too. Feeds to all legs plus 6 other feeders on a very small 2' x 4' layout of 2 concentric ovals, the double x-over, 2 #4 RT and a #2 wye. 1 of the 2 loco's brand new Atlas SD35 other is a BL F3 bought 11/20. Wheels appear ok and seem aligned. Track cleaned every 2 weeks. Placed level along route with level center with x-over center. Bubble within line in both cases. Removed and flipped vertically, same issue. Tried brand new double crossover - same problem either orientation. Any idea's?