A large update has just gone out. This update is an overhaul of the animation system. There is one known bug where a two-part avatar (body+head) may have its head rendered slightly off. We’ll fix this bug after the merge. If you’re affected then let us know and we’ll probably try to fix it sooner rather than later.
Details on the update can be found here: https://github.com/highfidelity/hifi/pull/5438