This may just be another manifestation of the monorail power bug but it works slightly different from what I saw described.
So, I built a monorail system from one base to another. The bases were already connected with Cables at this point since I built that system first.
The monorail worked like a charm without issues for quite a while. At some point I noticed resources piling up, and when I looked I saw the monorail had stopped working. One of the end-points now said it had no power accessible although as has been noted before there is power.
Now both those bases already are setup with their own generators. In that particular base I built at least 3 levels of powered blocks and the monorail terminal is toward the top, whilst the power generator is at the bottom on top of the water. In this case I built up and am using the generators and waterwheels (in addition to a lot more built by me) that were already present by the giant hole that pours water down (sorry I forget the place-name).
I've tried shifting the position of the monorail throughout various parts of that base, even building new portions of powered floor for it to no avail. I simply can't get it to sense power.
Later I also tried building generators by the freight elevator and putting a monorail in that area, and had the same issues. I can't get that monorail to activate. As of right now the only one that I can get to power is over by Victor. THAT one works, but 1) it's the end-point, and 2) none of the other monorails I place work.
Any ideas?