A couple of things that I have noticed about the scrolling lag:
Adding to the thread so I can follow the replies. I am also experiencing the issue after updating to Sonoma. Scriv is 3.3.6. Great program, by the way.
I can confirm that the behavior does not manifest in composition mode. I use the sidebar a lot though, along with project bookmarks etc, so that’s not really an option for me. Thanks for the great program. Hope you figure out the bug.
Adding myself here because I’m seeing the same problem. It’s maddening. Only happens when I’m using the trackpad. Is there nothing to be done until Apple fixes it? Should the developers file a bug report with Apple?
I’m hypothesising here.
The new Apple architecture refreshes at 120 fps. What happens if for Scrivener you set the operating system (MACOS) refresh rate to 60 fps. Would you experience the same lag?
If I’m on the wrong track, tell me and I’ll accept that.
By the way, if you just want to subscribe to a thread and receive updates, you can click the bell icon and then select either “Tracking” or “Watching”.
But yes, how the trackpad works is way beneath any code Scrivener is made out of. If anyone that can reproduce it is also capable of installing the beta OS to an external drive or additional internal volume, that would give us a preview of whether they’ve worked on it. Unfortunately I can’t see it, which is likely because I don’t use a 4K screen but also use an M2 chip. The combination of higher system power and much lower display requirements means everything is lightning fast and input never locks up.
Try turning off inertia scrolling in your trackbar settings. Just search for “inertia” in System Settings. Also turn your scroll speed down to about 3. The problem is not solved but it is much more responsive.
do you have a liaison at Apple you can talk to? I’m wondering if they even know there’s a problem.
We do, but it is not their role to hear about every bug we come across; that is what the Apple bug reporting system is for. If it is determined that is the nature of the problem, this is where it will be filed though, absolutely!
I don’t understand how downgrading to Scrivener 3.3.1 fixes the problem if it’s an Apple issue. 
An issue that requires carrying around a mouse everywhere for the sole purpose of making your product usable doesn’t strike me as fitting into the category of “every bug we come across.”
If my own experience is typical, this is problem is sufficiently acute as to induce someone to consider abandoning the software entirely. It is unquestionably that aggravating.
I am no longer in a position to recommend macOS Scrivener because I have no idea when this will be fixed, which is a pity, because it’s otherwise such great software.
Maybe I’m wrong about this, but after the last update (I’m on Sonoma 14.6.1), this problem seems to have largely resolved itself. Did Apple fix the bug? Can anyone else confirm?
It appears to me that the 14.6 update helped a lot, but it’s not completely fixed. At least I’m no longer shopping around for another writing program. Scrivener is usable again. I haven’t put the 14.6.1 update on yet.
The fact that L&L itself appears to have no interest whatsoever in discussing with Apple a problem serious enough to drive many users into considering abandoning Scrivener entirely is disappointing to say the least, and a bad omen for the long-term success of the application, if not the company itself.
Just a simple “we’ve contacted Apple and confirmed that fixing the problem will indeed require an OS update” would have made a major difference. Is this really too much to ask?
This issue has caused nine(!) months of persistent aggravation to some sizable fraction of the userbase.
I’d be curious to hear if anyone in this thread that has experienced this problem persistently, has any updates on whether it continues in the macOS 15 build (in beta at the time of this posting)? By that I mean, please do not install a beta OS because of that question… only if you already have it installed for better reasons! 
I’ve personally never seen it happen, myself, so I cannot really say whether it is better or worse. I can scroll half a million words of content in a massive Scrivenings session at lightning speed and stop on a dime every time. This is with a standard resolution monitor in an M2 Mac though, which might mean there is too much processing power against the relatively small number of pixels for it trigger.