Hi guys, first post here after not having much luck on Reddit; I've submitted a support request as well. Really want to get to the bottom of this on a few places so anyone with the same problem can find a solution.
I don't have permission to post links, but if you search the reddit post "Animation glitches when turning or starting to sprint" on either r/skyrim or r/skyrimhelp, I've posted a link to a YouTube video. You could also search "Movement Animation Bugs in Skyrim" on YouTube.
The first issue is that weird instantaneous turning that seems to plague walking on this game, and really shines when using an Xbox controller, like I am there.
The second issue is that for just a single frame when I start to sprint, the character animation reverts to walking. You can see this most clearly if you pause at around 00:09.
There is one mod installed (Fires Hurt), and minor tweaking in .ini files, however the problem persists on a fresh install of the game with a completely fresh character, with Steam cloud sync switched off so nothing can get carried over. I manually deleted the Skyrim folder in Documents/My Games, and any remnants in program files in between installs.
All DLC is installed, and I've also now tried USLEEP. All .esm files are in the right order, and I have an i7 4.0GHz processor and a GTX 1070. The problem persists on a separate computer, 3.0GHz, 460GTX.
Any ideas guys? Thanks in advance