Hey Dave,
what @ChrisM suggested above, is to clamp a block somewhere on your workarea, that can be left permanently there, away from your work, and to use the touch probe on this block in order to substitute homing with a more reliable method. Unlike when using stall homing, this block never moves and repeatability should be excellent.
Regarding problems when using the touch probe, you should be able to eliminate them by taking care to clean the bit and the inside of the collet before probing so the electrical connection is of good quality, or if errors come from the flutes, even better use the shank of a bit that you inserted the other way around into the collet as the probe to probe X and Y (and use the real bit only to probe Z).
If you had such problems there could also have been a problem with the probe wire. I would not give up that fast, since when everything is in order, the Touch probe brings excellent results.