Hi there
I suspect this may be an issue with transients on your site. You can use this plugin to delete all expired transients and see if that helps:
https://wordpress.org/plugins/transients-manager
Thank you Dan,
I deleted ONLY expired transients and now Jetpack widget stats give the following message:
“An error occurred in fetching stats. Please retry later”
Admin Jetpack stats work well as usual
Hi,
After deleting expired transients I disabled W3 Total Cache, disconnected and reconnected Jetpack, enabled W3 Total Cache again and purged cache and the problem seems resolved! Stats are now correct, I will see if they keep up to date
The problem seems definitely solved, many thanks!