I can't tell whether it's light leaks in the camera, fogging from loading the reels (I use a bag but maybe a leak), not enough developer in the tank, or all of the above. Any opinions would be much appreciated.
are those areas processed?
Edges should be clear. Are they? or are they fogged?
Could it be that the paper was not wrapped tight enough when you taped it after you exposed the roll? (it looks like 120 film)
if you haven't discovered the problem, i'd suggest light leaks in the camera, since it is happening in the same place on the negative, (if i'm seeing that correctly).