Navmesh agents and agent radius question

i have 2 ai’s with the same radius, one for land and the other for water environments. i have made two separate agents as i want the recastnavmesh’s to have different settings to allow for the ai to move through their environments correctly.

Whenever i try to build my navigation with 2 agents with the same radius one of the navmeshes is never built.

is there something i am doing wrong? is it a bug? is there a better way to achieve what i want?