We have recently been having some hits (just a handful a day) to `<ourdomain>/stock-problems`. We previously had this issue when we were tracking stock. However, we now don't have any items tracking stock (or at least, if I click Admin -> Products -> Inventory then there is nothing listed). Why could our customers be facing stock issues at checkout? Or how could we gather more info to diagnose this issue? We have HotJar installed, but as the recordings drop off before checkout, it isn't much help.
You might want to go to 'Products' > 'All Products' and check under Inventory column. All products should say 'Inventory not tracked'.
Hope this helps!