This might be a librecad issue. I’ve had problems with files where I laid down lines exactly on top of each other in librecad. I can’t see them in my file but ESTLCAM does and they end up defaulting to a different cut style since I never actually select them. Say I select the line that librecad laid on top and make that and inside cut, ESTLCAM will default the lines underneath to outside cuts and I get exactly this issue. You might try making a super simple file in libre with a square deliberately laid on top of another square and see if you get this.