Seems like it could be the same problem I had.
Are you 3D carving, maybe importing an STL and/or vector files created in sophisticated/professional CAD software, with a lot of nodes/ detail?
The buildbotics controller is running on the Rasperry pi, which is a very weak computer that cannot necessarily handle complicated files.
I upgraded to the Masso. I have never had a problem with the controller failing since, I strongly recommend upgrading in your case. The Buildbotics might work well for hobbyist, but cannot handle too much data.
I would never know beforehand when it would loose steps, which resulted in a few nice blanks become firewood. I lost trust in the buildbotics controller
I had the same issue, lost steps mean that the controller loses the machine and hence also the work X/Y. It may then run into the limits of your machine. In my case the profile toolpath had too many nodes/too much detail.
The solution for now would be to reduce resultion somehow. I do not know which CAD/CAM software you are using. For example in Vcarve a possibilty would be to reduce the modelling resolution, for example from Maximum to very high, high or standart. You will lose some detail.