I must say that I am not happy with the way HMD Global has solved the handling of dual SIMs in their phones both feature phones and smart phones.
The problem that I run into is voice calls. With the SIM manager I can choose with which SIM card I want to make phone calls. But this setting then is set and cannot be changed shortly before a phone call (unless I go to the SIM card manager again, of course). But when I choose "Ask before each phone call" in the SIM card manager, the phone is useless when attached to a Bluetooth handsfree kit, because when I want to make a phone call from my cars head unit, I have to take the phone out of my pocket to choose the SIM card with which I want to make the phone call. This is a no-go while driving a car.
It would be better, if I could set the preferred SIM for phone calls with the SIM card manager but then still have an option to choose the other SIM card during dialing. If I don't use that option, automatically the preferred SIM card will be used to put up the phone call. Options to temporarily switch the SIM card could be e.g. by a right softkey with Options or by long pressing the green button (off-hook) etc.
This is pretty much the way the handling of dual SIMs is realized in competitor products (e.g. Samsung).
Thank you for listening, HMD!
I also have problem with the Dual SIM Handling under 8.1.0 on my Nokia 8 (german) - I have my Swiss Sim on Slot 1 (deeper in the phone) and the local SIM as #2. I can set preferred SIM for Data and SMS but NOT for voice. It does not accept the fixed choice to use sim #2 nor does it accept the choice always ask. So when I want to make a call with sim #2 I have to deactivate sim #1 - a bit annoying. Thanks, Walter