Messages and SMS from a dual SIM phone

[Aseel67]

When sending a message from a single SIM phone, the message is delivered normally. However, when replying from a dual SIM phone, the message does not reach the recipient at all.

Is there a solution to this problem?

[nfdz]

@Aseel67 Thank you for reporting this issue. I think I understood the issue:

• Given a phone A with dual SIMs (the one that sends) and another B with one SIM (the one that receives)
• A sends an SMS
• B never receives the SMS
  Does any encrypted message appear in the system's messaging app? (both phones)

[Aseel67]

Phone A carries two SIM cards
Phone B carries one SIM card

Phone A receives encrypted messages normally, but when replying to phone B, no message is received and does not appear on the official phone app