Not known if you have this sorted yet or not.
This may to be a limitation in TC surfaces used in both pro and deluxe. and seems to be caused by the bottom of the V, where the small V shapes meets the ones cut width-wise, , in v16 (not 2016) this throws up a degenerative error, but it seems nowadays a change in programming means the part is converted to surface/sheet instead of throwing up an error.
There are some workarounds, depending on what tolerances you have, one would be move the small v shapes up very slightly, say 1/100th, so the bottom of the V's are not coincident. and try that (may need more than that). a second workaround could be to, cut a longer groove and then fill in excess afterwards , there is a sight chance of getting a degenerative error, but it works for me.