153.5 esr has broken a lot of things, autoscroll, menu spacing, etc etc

Since today's update to esr 153.5 a lot of things have changed for the worse. One annoying thing is that Firefox always opens now in Minimised view...why? I've never used Firefox Minimised...so now every time I have to click Maximise. Another one was that the Hamburger menu items suddenly had huge spaces between everything...at least I was able to find someone on Google who had a css to fix that. But the same thing is happening in the right click menu also, I had a css for that for years but now that doesn't work. The other super annoying thing is the scrolling has totally changed, I always used to uncheck 'smooth scrolling' and check 'autoscrolling', although I never use what they say autoscrolling is supposed to be about...something about holding the middle button on the mouse?? All I know was that setup used to make the scrolling in Firefox excellent...now it's basically annoying smooth scrolling whatever I check or uncheck. The other thing is after this happened I uninstalled Firefox altogether, and reinstalled the 150.0esr version and all this stuff is the same...even though I was previously on 153.4esr...and it wasn't happening on that? So I suppose I might as well just update to the latest one then? And just put up with all this annoying stuff. By the way, I'm still using Windows 10...not one issue a year after all the doomsaying from Microsoft [Defender still gets security updates anyway?]...which makes me wonder about the so-called 'security' issues with using an older version of Firefox. Thanks, any ideas for ways to fix these things would be very much appreciated. Especially the scrolling thing.