I've begun to notice that despite their being no signs of a conflicting personality within Cyn any time you speak as if Cyn and the Solver are the same thing or that Cyn is evil or fucked up in some way people will immediately begin reeeing at you and then spouting their retarded headcanon about how Cyn used to be normal before the Solver even though the show presents no evidence of this. Like yes, okay the show does imply that Cyn made a deal with the solver and willingly allowed it inside her but we know literally jack and shit beyond that, we don't know any details, how much this control entails if Cyn is really just an avatar for the solver or if Cyn was ever even her real name in the first place. My point is people seem really averse to the idea that Cyn is just fucked up and evil.
CYN is effectively a lifeless corpse reanimated by an evil entity to be its vessel. As you said, there is never a moment in the show where the body of CYN would express any other personality than Solver's. The only things the show tells us about the original drone is that it was discarded at one point for being broken, its part number starts with CYN-N, and it agreed to get possessed by the Absolute Solver (or just accidentally pressed the enter key, something I do all the time). This is all we get to know about CYN, and it was shown in the first 80 seconds of episode 5 in such a way that it's no wonder most of the fandom doesn't understand anything about either of the two.

Do you see that second screenshot with that very important piece of lore on it? It was on screen for less than half of a second. I had to put the video on 0.25 speed so I could pause it on such a frame where all of the text is present and legible, so it's even less than half of a second effectively.
I also tend to look at various leaks, and not even those address anything about CYN before meeting the Solver (I believe). CYN as a character doesn't exist within the show; it was "alive" for less than a second, immediately let the Solver take full control of its body, and then its story literally ends there—we never see the original drone act on its own or have a say in anything ever again.
But because the cartoon didn't do a good job telling this to an audience in which most of people are dumb as a rock, we have to suffer the consequences of people thinking all kinds of stuff about CYN and the Absolute Solver. No wonder people keep making up all of those headcanons when they have a hard time distinguishing those two.
Oh also I hate to bring up Murder Drones again
No problem. There aren't really any other places where you can talk about this show without being dogpiled by insane Tumblritas and dumb children for disagreeing with them (or if there's one, I have yet to hear about it). I tried using 4chan to avoid those two groups, but the threads there are so bad that they got expelled from /co/ twice (oy vey). There's nothing there worth seeing—you will only find endless coomposting (half of them are done by Xitter artists browsing those threads) and pointless drama related to an altchan they colonized after getting shoah'd for the first time. Say anything negative (literally anything negative) in their threads once, and they will accuse you of being one of their boogeymen, thus derailing the entire thread for hours at least.