We are facing issue in sendbord call (Android to iOS)

// Detailed description of issue.
We are facing issue while calling from android to iOS

// If problem, please fill out the below. If question, please delete.
[SDK Version]
// What version of the SDK are you using?

[Reproduction Steps]
// Please provide reproduction steps and, if possible, code snippets.
Just call from android to iOS

// How frequently is this issue occurring?

[Current impact]
// How is this currently impacting your implementation?
My application is based on internal communication of employees of my company and if it not works my application is not useful