Ok so this just happened to me again and I did both the method of changing it in the tool manager and regenerating tool path and it worked. I do believe that just regenerating will fix the problem at this point.

I have now had multiple instances where after I edit a tool number in MasterCam 2018 it will not recognize the new tool number and posts out the old tool number. The only remedy I have found thus far is pulling a new tool from the tool library and changing the tool number before creating the path. Has anyone else had this issue or am I the only one seeing this.