Faulty URL in Ad redirect

A tricky one. Ever since the 5.x update, I see this error in the system log almost every day:

Some guest clicks on ads have an invalid URL (apparently because of an additional apostrophe added to it). I can’t actually replicate that error though when clicking all ads myself, so I understand this is tricky to narrow down.

It’s worth mentioning that I mostly deliver ads through the new ad widget, including Pages ACP versions of it.