I could be wrong, but I think you need to be very specific about which exceptions are not logged. Remember that Outsystems "bubbles up" exceptions so if you have a specific Exception and set the handler for that specific exception to be "no", you may still get a log from the parent exception of your specific one.
For instance, setting a User Exception to not log will not result in a User Exception log, but the All Exceptions log may still get written. That's where I would start my search.
Otherwise, I would be happy to take a look at your OML or a screenshot of your exceptions settings.