I had on occasion used some G-Code that was a previous users slice or a sample Sliced G-Code.
OR
Different slicer not configured correctly for my 3D Printer anyway somehow it changed some of the 3D Printers settings.
Then G-Code that I had previously sliced would not print correctly even newly slicer STL files failed..

That is until I purged the changed 3D Printers settings and restored them to the Factory Defaults.
Was about ready to throw away many partials rolls of filament thinking they had drawn moisture or just went bad...