This appears to be a bug in macOS 27 Golden Gate. Bugs should be reported to Apple here:
Feedback - macOS - Apple
I will note that I can only partially replicate your issue. On my Mac running Tahoe, in the Mail app when I drag an email onto the sidebar and scroll with two fingers, the list of mailboxes scrolls. That does not happen on my other Mac running Golden Gate. However, on both Macs when I drag the email to the bottom or top of the visible list of mailboxes in the sidebar, the list scrolls down or up, as appropriate.
In Finder, the behavior that I see is the same in Tahoe and Golden Gate. Dragging a new item into a folder, I can two-finger scroll on both OS versions, and dragging the item to the bottom of the list scrolls the folder (in List View, at least).
So for me, the two-finger scroll on the sidebar in Mail is a reproducible bug.
Standard troubleshooting for issues may help with the other scrolling problems you are seeing.
Have you rebooted your Mac? If not, that's the first step. If that does not help, then see if the problem is present when you boot in safe mode. That process performs some system cleanup and clears caches, and also disables 3rd party extensions that may cause problems.
Start up your Mac in safe mode - Apple Support
If that does not correct the issue, test in a new user account. A newly-created user account will have all settings at default, and if the issue does not occur in that new account then it provides guidance on what may need to be changed to correct the issue.
Add a user or group on Mac - Apple Support
Once the testing is complete, the new account can easily be deleted.
Delete a user or group on Mac – Apple Support
Those steps will help to isolate the problem.