As discussed on the LFN Dev and testing forums, some of the RTD branches were not activated by default therefore the docs were not getting created. This can be solved by using Automation rules.
For instance, I have created automation rules for Netconf project for activating
all tags/branch matching this regex: "^[vV]"
Custom match: ^[vV] Version type: Tag Action: Activate version
Custom match: ^[vV] Version type: Branch Action: Activate version
