That makes sense. Anything that matches "{cultureCode}/{nodeAlias}", also matches default routing and as long as default routing is registered first it handles the request.
You need to adjust routing templates, so they are different.
Option one: change new route to something like "{cultureCode}/content/{nodeAlias}",
Option two: make action in default route required (remove default value for it)
I understand that none of the above options might work for you, I'm trying to provide you with idea of why it doesn't work and what could work.