A very specific problem, with a dead simple fix.
I've been having a problem when using Hootsuite on my MacBook Pro, that I couldn't scroll horizontally across my streams using the two finger swipe gesture on the trackpad when using Chrome.
TL;DR - Clear your cache.
This has been plaguing me for a little while. Chrome is my browser of choice and the problem was only occurring with the built-in trackpad. Safari worked fine and everything worked fine even on Chrome when swiping left/right using an Apple Magic Mouse - which I normally do.
This morning, I worked out that I *could* get the horizontal scrolling to work IF I attempted scrolling when the mouse pointer was positioned over a blank space in a stream, rather than a post. For some of my more sparsely populated tabs, this was kind of helpful, but not in the busier tabs and streams.
With advice from @Hootsuite_help (and I should have tried this as a first step anyway), I tried logging in to Hootsuite using an Incognito window in Chrome, which worked as a test. This clean browser window ruled out a lot of things and suggested a session issue. Clearing my browser cache, and logging back into a regular browser window restored full two-finger swipe gesture functionality. Hoorah!
A short post, but I struggled to find anyone else who'd had this problem. I hope it helps others.