Error G10 L20 - help

When entering G10 L20 P1 X0 Y0 according to the documentation, the current coordinate should become zero coordinates, I load the test program of the square
 
it is obtained - the trajectory is shifted relative to the design one, and at each G10 the L20 can be shifted only by Y or by XY
 
Similar when using G92.
 
If you specify as an offset from G10 L2 P1 X100 Y100, the scheduler and tool paths match
 
The question is - what the hell? .var and bak.var deleted, tools removed from the table, the result is the same... Please help
lcnc last 2.8.4
 

try G10 L20 P0 X0 Y0 or reload G54 after  G10 L20 P1 X0 Y0. But check your Z-Axis point. Maybe it's zero if you not set... 

I'm not considering the zet at all, trying to defeat the XY
Now he generally shifted by mm, on the screen it is clear that by G0 X0Y0 arrived at the center of coordinates, and the circle of the tool is shifted from the contour
 
 and immediately conducted an experiment with G10 L2, then also sent to G0 X0Y0 
 

This is a Gmoccapy bug, the same for several users on lines and arcs in 2.8, and in arcs 2.9. I hope the Gmoccapy developers will pay attention to this. Axis has no such problem.

We have seen something similar in qtvcp (they use common graphics library).
after a g10 in MDI the display is reloaded but the offset of the program does not happen.
It seems to be the internal offsets are not updated - we added a mode switch to manual or a task resync and it helped but there are still problems on g55 etc.

It would not surprise me if gmoccapy/gladevcp has the same bug.