So, if the max file size is set to 2047mb, it works fine, and lets upload large files, but when its exactly 2048mb, it limits the members of that level, to only be able to upload a 2kb file within the messenger.
Thanks you for the details! We will think over the all described issues above and will add solution. I think, we can use Settings option which is available for talk's owner in info menu button, something like - Allows to join for everyone.
I have tried that still get the same error "Cannot perform the action. Please report.". I have checked with paypal they confirm I have the right public and private keys so they say its a developer problem.