LF and VLF is mostly ground wave but can have skywave activity depending on solar activity. The old Loran A is a prime example. At night, you could see a trail of skywaves on the scope. Multiple hops with time delay. When you reached the end of the usable ground wave, it was gibberish peaks. Atmospheric noise peaks in the summer on lower frequencies. It’s possible the stations in the U.S. and Canada may have experienced storm interference that’s not uncommon this time of year. So many variables.