Regardless of how the phone is now running Q, the “normal” method to go forward to upgrade to R would be to clean install eOS-r-0.18 manually from freshly installed e-recovery bundled with the OS on the downloads page, carrying out a factory reset/format data in the process.
You shouldn’t get offered any updates in the system updater on eOS-R if you are/were running the 31 Aug build because this is the latest available version for the device. If you did get those Q updates then as aibd says: it is an issue.
It is however confusing in a way that Q is getting all the updates at the moment! The situation should normalise once the R rollout is complete I guess.
Looks like the next update for R will be in January and it will be a jump form the current 0.18-r to version 0.21-r: