Can Firefox Focus handle typical Rinjdael (AES)-256 bit d/e[n]cryption protocol for secure cloud storage providers? i.e. dling/decrypting content in-browser?

While attempting to decrypt files locally on device (Android 7/Linux), from a secure cloud storage provider offering a zero-knowledge paradigm with the Firefox Focus app on Android 7, it seemed unable to handle the golden standard of encryption algorithms utilized for encryption protocols (AES-256/Rinjdael) while attempting to download content from a secure sharelink when successfully authenticated, the files would not properly download and decrypt though the encryption key/fragment identifier was properly appended to the secure sharelink, and the website appearing to be functioning nominally/OK, unexpectedly lead the app to terminate upon attempt of initiating the download/being unable to process the d/e[n]cryption protocol, from my observations.

Is it possible for this kind of enhanced privacy browser enabled support/handling of basic encryption in such a similar scenario, and downloading from secure-cloud storage platforms in such a precise occurrence likely to be included in future releases? (AES-256 capable).