Normal Map baked in Marmoset, renders correctly. Also there are no problems in Substance Painter and Blender (Eevee). Seams appear when switching to Cycles. What is the problem?
Maybe play with autosmooth?
Is your baked normal map’s color depth set to 16-bits?
8-bits normal maps are known to sometimes cause artifacts for seams.
I tested 8,16 and 32 bit maps, no difference.