I upgraded to Build 3197 yesterday, from 3176, on Kubuntu 18.10.
Under some circumstances, the pane no longer scrolls via mouse scroll-wheel. Page up/down still work, and otherwise the editor is unaffected. Under all circumstances listed, clicking on the Sublime Text window fixes scroll. Sublime Text is the only affected program.
Circumstance 1: I have focus-follows-mouse enabled. If I mouse over the window, it gains focus (keyboard, etc) but the mouse wheel no longer scrolls the buffer.
Circumstance 2: If a Telegram notification pops up, scroll similarly stops working until I click on the ST3 window.
I have bought ST3, and it does show as licensed, so I doubt the popup for that is causing issues.
Packages installed are: Anaconda, anaconda_rust, Babel, ColorPicker, Evaluate, Indent XML, IndentX, LESS, Package Control, PackageDev, Pretty JSON, SideBarEnhancements, SublimeLinter, SublimeLinter-eslint, and Theme - DefaultPlus.