I removed the if statement to prevent the code from being applied based on the bed plate.
It is not a hardware issue; the G-code (G29.1) itself is not taking effect.
I might also add that the the offset is probably limited as in trying to offset values high that say .5 will be ignored. There should be no reason to offset 5-10mm like your trying to do.
Values with a plus sign or brackets will also be ignored.
I have also tested the commands without parentheses or plus signs. Although I didn’t mention it in the original post, I tested values ranging from G29.1 Z-0.01 to G29.1 Z-0.05, but none of them took effect. Furthermore, G29.4 does not exist in the first place, and using G92 is not viable because it ignores the bed leveling mesh. Rather than searching for other workarounds, the proper approach is to modify the firmware so that G29.1 works as intended.
What do you mean? This isn’t just an issue on my end—as shown in the attached link, other users are experiencing the same problem. Bambu needs to either investigate whether this is a hardware defect or fix the issue through a firmware update.