What went wrong?
Based on testing, when using Sync Strike, UB and spamming a non-dual wielding Shadow Cascade almost simultaneously against inclined terrain, the Rogue’s running animation bugs out until you leave the area or use an ability.
This was a bug I was easily able to reproduce multiple sequential times too.
Seems like this might be an issue common to very specific sequences - e.g. You can also cause a similar issue with movement skills on Sentinel characters too - its harder to “force/reproduce on demand” but the resultant movement is exactly the same as your Rogue example. Your way of reproducing it more reliably will undoubtedly help the devs trace the cause…
I have taken to knicknaming it the “ice-skating movement bug”…