In my opinion,
you just found different R and not in the same place.
I see no problem in outputing R1000., R10000. etc... diferent tolerances - one time it see arc and with other tolerances it doesnt.
Different tolerance in operation can caused different paths. Normal.
1*Just check the R address if there is maximum/minimum and it is set like you want.
I suggest keep it "open" for biggest number.
2*Check also format the R is using.
3*If you machine dont accept such big values -there is minimum and maximum R value that can be generated.
Set here the maximum R your machine accept.
4*Also check this value in postprocesor:
You have to have these settings on your mind and mix it together well.
If there is no bug, I believe Ive mentioned all what you can adjust for your R output.
Keep in mind that very small minimum radius values and very large maximum radius values can cause errors because they can result in very small interpolations which the machine is not capable of. Also, if your part model has some issues, this can increase the likelyhood of arc errors at the machine.
At other companies I have seen posts configured to be more tolerant of machine behavior and bad geometry. They minimum radius set to .010" and max set to 500." which eliminated all of their arc problems. The settings seem drastic to me but it works for them.
Note in Step "3*", the dialog to set the machine's min/max radius is (for Post Builder):
Program & Tool path -> Motion -> Circular move
Production: NX10.0.3.5 MP5 + patch/TC11.2
I'd rather be e-steemed than e-diseaseled