Site Navigation Update Takes Two Tries

I keep running into an issue with site navigation where my changes don't "stick" all the way. (Note: this is not hub nav, this is individual site nav)

When I add new items to the nav and move them where they belong, they will usually get created... but they will be moved all the way to the bottom/end of the list, forcing me to re-edit the navigation a second time to put them where they should be.

I am an admin on a tenant with hundreds of sites, and I spend a lot of time teaching people how to update their page... this has gotten extremely frustrating to explain to users. Does anyone know of a reason why this is happening, or perhaps something I can do differently? Or are we just stuck editing twice?

Thanks!