Apologies, Keith. Dealing with Roll20 has been a bit... infuriating at times lately. I shouldn't have snapped at you. I've been using Roll20 for a bit now, with tokens and familiars and everything with sight and darkvision and all that, and I'm seeing new, buggy behavior as of last week or so--intermittent enough that it could have snuck in a little while before, but definitely not 2019-era. I've been making all my bug reports by forum, too, and was concerned that a bug report might not be taken seriously. I've gotten a bit tired of having to reopen and redescribe other bug reports every few months. And since I was in the middle of managing a game day, complete with missing players and balky Discord connections, I didn't do a great job at describing my problem. I'd meant to see if anyone else had seen the issue, too, and even that didn't make it in my post.
Part of it was apparently confusion on my part, of course. I started using Roll20 in 2015, not far from this update, which looks to have separated out z-ordering by sight. With almost every game I've played in using dynamic lighting and sight, I guess I've just always had the experience that tokens you control appear over tokens that you don't control? It's hard for me to figure out if there were any cases where that didn't work that way--I don't remember any, but that doesn't necessarily mean anything. Nobody in my group can remember a time when a token they had control over was hidden by another token, even. But then, I can't even find any to-front or to-back documentation showing up before your work on the z-ordering article in the wiki. Makes it hard to rule out a Mandela Effect.
In any event, whatever happened in 2019 passed me by while I was blissfully unaware. I saw zero change in behavior from that update and had no idea it had even happened!
Anyway, I'm sorry! You do a ton around here and I didn't mean to be so rude! You certainly don't deserve it.
Separately, I've gone and made a Help Center report. We'll see what happens with it.