How tight of a corner...

I have been trying to cut out a 3D puzzle of a dumptruck from 1/4 plywood.
The first time I cut it, the inside corners wer too round to get everything to fit together.

I thought it might be the 1/8" bit so I tried again with a 1/16"
Same problem, but this time I zoomed in to the display as it cut.
I noticed that while my Gcode cut lines were closer to 90 degree inside edges, the white line drawn by the cutter as it moved thru the program was cutting the corners short.

So now Im wondering if this would a setting with Linux CNC, speed maybe. Or maybe a limitation of my machine itself. It could be the drawing, but since the path wasnt really following the Gcode perfectly I tend to think its not the drawing.
Any ideas?
thanks

this is more to do with creating the gcode via the post processor and in part to the drawing ,
linuxcnc or any controller for that matter , can only follow what it is told .

not knowing the procedure or program you are using to produce the gcode it is difficult to advise , but remember you are using a rotary cutter therefore 90 degree corners need additional processing
without this you can only produce a rounded corner to the radius of the cutter being used

making outside corners more of a 90 deg it's simply a matter of going past the point and moving off , say at 45 deg to become inline for the next cut , this then gives you a square corner
inside corners of course are more difficult and require a small cutter , as you cant cut into the radius of the cutter

remember the line shown in Axis is the line of the centre of the tool Axis , and not the cut path which is essentialy half the cutter width again , so for example the cutter would stop 1/4" ( cutter radius ) short in a corner if using a 1/2" cutter
this can at times be confusing hence why if cutting say into a 45 deg corner the backplat would show a sharp corner , but the work would have a radius determined by the cutter

Thanks for responding.
Im extremely new to this. My skill in all areas are very limited.
Ill def review those links.
I draw in Sketchup & use a script, sketchucam, to gen the Gcode.
I think I can draw plunge points or circles around the corners to solve the prob.
Ill read & experiment further.