A correction: when double-clicking the foreign key in the data model, rename, and save, it does seem to be updating the project browser...
But when double-clicking a relationship in the project browser, or by right-clicking the table and selecting operations, and changing the name this way, it doesn't take.
But the weird thing is it seems to be one step behind of the changes, and certain interactions I'm doing does update it. For instance, I change a name from PK_A to PK_AAA in the data model, and it works. I change it from PK_AAA to PK_B, it doesn't work (still shows PK_AAA).
But something I'm doing is causing it to work because it eventually shows PK_B, but I'll change it to something else in the project browser and it still shows PK_B. I can't explain exactly what is happening, but it's definitely a bug...
Thanks.