What you might be experiencing is corruption of your DCC bus signals. These little devices are designed to fit as a pair to the ends of your DCC bus. You don't need more that two regardless of how big your layout is.
DCC Concepts DCC-TAG25 Power Bus Tag Strips (25)
DCC Concepts DCC-Tag25 Power Bus Tag Strips (25)
Hydra DC and DCC 16 channel bus bar with isolate function
DC & DCC Layout Dropper Bus Wire Model Railways 1/0.6,7/0.2,16/0.2,24/0.2,32/0.2
DCW-6WC DCC Concepts Accessory Bus Wire per metre 7x 0.2mm 6 Core
NEW RJ12 6PIN BLK DCC RAILWAY CAB BUS & POWERCAB CABLE - VARIOUS CABLE LENGTH
