I'm thinking, perhaps, that some of the segments of Falls Rd are set to Rank 4, and since these segments are auto-selected when doing house numbers, the editor may see this as a permissions issue.

Can you find a segment somewhere else which is a different road, rank locked above yours and try to add a house number?

I think you may be on the right track. Although I found a stretch of road locked at a higher level than I am and I was presented with a "View House Numbers" button vice a "Edit House Numbers" button, so clearly waze is aware that if a section is locked, that includes house numbers as well.

My parents live in a rural area near Modesto California with the same situation. They are a long ways from the road that has their address. You have to drive down a shared private road to get to their house (and to a number of their neighbors that share the same access road).

I haven't attempted to correct Waze's idea of where my parent's house actually is since I already know, and I'm used to GPSes just getting to the intersection with the private road.

There is a highlighted area around the road which shows the maximum distance from the road where you can place a house number. I run into this problem a lot, as I live/edit in a rural area. What I do is I try to place the house number as far away as possible from the road but in line with the correct building, so that it's (presumably) easy for a driver to tell which building it is.

Seems like in this situation, however, it is a building behind another building, so I'm not sure quite what the solution is.

Here's another solution I made recently in response to a driver-submitted error about 10364 Old Frederick Road:

https://www.waze.com/editor/?zoom=6&lat ... 95&env=usa

A pretty common thing in rural parts of central Maryland is to have several houses all numbered on the same street, but having to be accessed by a long, unnamed, shared driveway (the legal term is "use in common driveway")... so that, for example, 10364 Old Frederick Road may actually be a very long way from Old Frederick Road.

Here, I attempted to solve the problem by naming the driveway Old Frederick Road also, even though it is unnamed, and attached the house number to the driveway. I'm not sure this is the best solution, as it probably produces driving directions like "Turn left on Old Frederick Road" to which a driver might say "but I'm already ON Old Frederick Road!" and possibly report an error.

I don't know other house numbers on this driveway.