Dunno if this is the same, but we have trances, where we're stuck standing/sitting in the same spot, not moving (so we're told) for up to an hour. In therapy, we've come to the conclusion that during these times, no-one is 'out front'. We've had MRI scans etc for epilepsy or other physical reason, none found. It seems stress and destabilisation are the times when this happens. Once re-stabilised internally, this doesn't seem to happen. Maybe same for you? When things are topsy-turvy, this happens more?