It's not a tyFlow bug. The error is caused by your Checker map.
You have the x axis set to "Mirror" and tiling to ".01" which is causing filtering issues. Maps are not filtered in the view in the same way, which is why it's not visible.
You have the x axis set to "Mirror" and tiling to ".01" which is causing filtering issues. Maps are not filtered in the view in the same way, which is why it's not visible.