I added an existing table to app B from another app (A) and then added some rows to that table from within app B.
When I returned to app A (open in a separate tab), it alerted me to a schema mismatch, which made sense. The problem was that, initially, the resolve schema dialog showed the table schema being the same as the (old A) code schema. So when I clicked to say that the table schema was correct, nothing changed, and the schema mismatch alert remained.
Once I reloaded the app A browser tab, however, the resolve schema process worked correctly.