If a user clicks on a SP Page Builder PAGE menu item of the page they are already on, the URL adds /default to the end, which leads to a 404. Here's a demo (15 sec): https://www.loom.com/share/5741cbd285ff4373beba20c5c0928789?sid=67863eec-1e39-4fa5-91a9-9173b32cbb9f
I've have done extensive testing to determine that this happens when there is a module, i.e. Events Booking - Upcoming Events, in a SPPB PAGE.
Importantly, using the module does not cause a conflict when it's within an SPPB ARTICLE, only when it's in an SPPB PAGE.
This URL is an example: https://bobbarrows.com/transition-101 changes to https://bobbarrows.com/transition-101/default
This does not happen on a browser reload, so be sure to click on the menu link which is in the drop down (it's the only drop down menu).
I have been working with the developer of Events Booking, from Joomdonation, but he is unable to determine the cause because the link from menu item is not controlled by Events Booking. He looked at the routing code and thinks it's very likely the added default in URL comes from that block of routing code in the file
/components/com_sppagebuilder/router.php, possibly the block of code from around 84 to 91 which process $query['layout'] variable.
Please advise.