Thank you! Halleluja finally found the cause here. I have been chatting with the helpdesk for an hour and they kept telling me it was my custom code, my browser and not a bug. Despite it happening in 5 different browsers.
I have been using a Wacom for 25 years and literally never encountered any issue like this in a website. It is a Squarespace bug. The Console also displays errors in the logfiles on each click with a Wacom pen.
Strangely enough I have had periods when working with Squarespace when this was not an issue, and suddenly now it is.
