Upgrade your MX to 13.28. This fixes a lot of issues like this.
It is listed as a "Stable Release Candidate".
Welcome to the Cisco Meraki Community!
Issues with websites being miscategorized have been addressed in MX Firmware version 13.3 or higher, which should be available in Dashboard, under Organization > Firmware upgrades.
If there isn't any MX firmware higher than version 13.3 available in your Dashboard, or the issue persists after the firmware upgrade, then I would recommend you contacting Cisco Meraki Support by going to Help > Get Help > Email Support and submitting an Email Case. Our Support Engineers will be able to assist you further with this issue.
We did see this patch but the confusion lay in the fact it was a lower level than recommended in the help pages. We'll give it a go.
@CapeCrusader70, it is actually a higher level. It goes in numerical order.
30 > 20 > 10 > 3 > 2 > 1