If this is a redundant topic or posted in the wrong forum - my apologies; however, I have not found discussions related to a problem I have struggled with for almost a year.
I do not profess to be a rocket scientist (nor a gCode expert) but I have struggled to get a TLS to work on an Altmil with tool paths combined in VCarve Pro. The g-code created when saving combined tool paths was resulting in multiple and redundant M6 commands. gSender then processed these as redundant actions (causing a vicious loop of tool measurements). I had/have notes in the tool definitions (in VCarve) that result in VCarve creating redundant M6 commands.
Maybe not the ideal solution, but by deleting the tool notes in vCarve the resulting g-code is clean and runs as expected.