I do have a sim card and an e-sim both activated in my duo, that doesn't however make it a dual-sim phone where both sims are active simultaneously.
I've been using dual sim phones for years and it is a great sacrifice for me to have to check my second sim every day to see if I have any missed calls and/or messages.
I have now inserted one of my sim cards into an old windows phone because I need two phones.
If the next version of the surface duo doesn't have true dual sim I'll have to settle for a galaxy z fold...
same concern here, I hope that they can fix it in a software update in the future because I was using Samsung note 20 ultra before and yes it's difficult to check the other sim if someone tried to call me. smh