Level Automation Jumps Up To Unreachable Area occasionally

Hi all
Has anyone seen this? It has been a problem for a number of versions for me and it’s starting to get annoying.
When using a controller to write fader automation, occasionally the entire written line jumps upwards, and often the grab points are beyond the top of the track. The indication of it’s intended effect on the audio remain in place, but it ruins the automation when it happens. All help greatly appreciated. Thanks