Aeotec multisensor 6 motion failures

I have recently had FOUR Aeotec multi sensor 6 start constantly showing motion when there is none then immediately showing no motion again … ( even in a darkened box) Has anyone seen this before and is it a common failure?.. It seems odd that they have all started exhibiting this behaviour at the same time…could it be connected to recent smarthings hub updates ? is there a fix?
Originally I had the default device handler , and have now also tried a custom one (which is great) but it doesn’t fix this rather perplexing issue
screenshot of what is being reported attached

W Padley