Read receipt in Desktop App

Hello everyone,

my question concerns the read receipts of private messages in the Teams Desktop App.

I can see the read receipts from my colleagues, but not from external chat partners.

In the Teams Mobile App, I can see the read receipts from colleagues as well as from external chats.

Is there an explanation for this?
Or can I adjust something there?

Thanks for your comments.

Many greetings
André Diekmann