Uncaught (in promise) Error - in Forge apps using storage api

Can you provide anymore context? It sounds like it is something specific to how you are using storage.

Can you post a sample app that has the minimum viable code to reproduce it?

Alternatively, have you tried messing with your own apps a bit to use storage in a different/simpler way? Trying to figure out is it happening any time you are using the storage API or just for specific calls you are making?