This meta bug collects all issues regarding jump of the document canvas view (not necessarily caret) in Writer.
A code pointer to those who wants to fix the jumps: put a breakpoint to SwViewShell::IsViewLocked in sw/inc/viewsh.hxx (with condition !mbViewLocked), and look at the stack trace of the break after which the view jumps.
adding "viewport" in the title to more easily find this meta.