Same on PC with my xbox elite 2 controller. With default settings the inner dead zone is huge. After decreasing it, there’s now a dead zone between slow and fast movement and movement speed is no longer progressive. Dead zone → slow → dead zone → fast.
Duplicate Threat: https://eu.forums.blizzard.com/en/d4/t/bug-walking-speed-broken-after-latest-patch-on-ps5