Hey DLR,
I would say, the question is, where is your workpiece zero coordinate (regarding Z), and did you probe/zero it exactly where the workpiece zero coordinate is in your 3D model?
You have a G80 command. Have you checked G80 (Canned Cycles) → Errors?
Regarding multiple tools in one file, do you know my Aiph5u’s ‘tool-change’ routine (V2023-03-14)