Let me start by thanking you for this fantastic FREE tool. I use it a lot.
I have upgraded ST latetly to 2.3.1.0 - it starts much slower than prevously and it also have some odd behaviour that might give a clue:
1. It flashes two dialog windows. I manage to catture one which says:
"Extracting file... Extracting archive: C:\Users\<>\AppData\Local|Atlassian\SourceTree\g[......]"
2. I have pinned ST to my TaskBar (Win10). Once ST starts, it displays an additional shortcut on the taskbar.
Thank you