Edits are awkward in mobile Safari

Has anyone else had problems editing a post in mobile Safari? The “edit box” is really jumpy - it starts at the bottom of the device, then jumps to the top when the keyboard arrives, but half the time it jumps up again when the textarea gets “focus” and the other half the time it closes.

I’m also getting strange behavior when I try to scroll through a long list of categories on mSafari - will post separately