I found some old articles but nothing that worked for me.
I was able to send jobs from CC Free to CM without issues, until I upgraded to CC Pro. The button was no longer there, so I purchased the subscription and registered it, thinking that it may be a limitation of the Pro trial.
Just in case it happens to others, the only thing I did (by accident) was to recalculate the toolpaths from the file I had previously used with CC Free.
Simply disabling and enabling the toolpaths did not work. I had to make a change and let it recalculate.