Hope you're feeling better and are on the mend - and thank you for the chapter as always.
That "error" message was interesting; I'm interpreting this moment as Aoi giving a "massage" to Ami, then having some sort of (unbidden??) memory/flashback to her time with Isaku - which I guess makes the Error Message another instance of her being a "not-normal android"? That, or it's alluding to the buildup of sequences wherein she gained true sapience because of the programming (and conditioning) of Isaku.
I look forward to the eventual reveal as to why Aoi is actually sapient as a sexdroid, though. It's clearly a big mystery in the overall sequence of events, and makes it dangerous for Ami to have not reported her to the alien higher-ups.
The slow burn reveal of more and more tidbits of lore in the midst of the weird SoL cuteness of a clueless alien and "innocent" sexdroid co-habitating is a neat contrast of tone in the meantime, though.