Beacon name is separate from settlement name. You can have multiple beacons in a settlement. The beakon gui should give you an option to name one and the other, which ever beacon contributed more prestige.
Could be detected as roads for some reason? 1x8 I would guess is a road from a get go
Second one hard to judge.
Please keep in mind that my own settlement also lost settlement status for a short whike when I ploted to much 1 plot wide corridors and had to add quite a wider parts.
The other is partially 3 plots depth and 1-2 on other parts. I rarely square plots off in a box formation. I just place them wherever I need them for building or prevention of others building too close.
For example if roads are detected by checking number of plotted neighbour, your tower with max 2 neighbouring plots for each plot would be a road. Depending on implementation of road detection.