The Wiki contains very good instructions on how to create a U-turn junction so that the driver receives a ‘make a u-turn’ instruction.
https://wiki.waze.com/wiki/Thailand#U-Turns
Proposal:
If this junction also serves as an intersection with side road(s), the intersection should be built as a regular (link, TBD) intersection.
Downside: no u-turn instruction for a driver.
Upside: intersection remains simple to build.
Suggest to add the following text to the applicable wiki section:
“Only use these constructions for designated U-turns without any connecting roads.
If a connecting road is present, refer back to the standard intersection setup (link)”