I'm using my Nokia 7 plus since a couple of days with a Samsung 64GB memory card. On the first boot the phone downloaded all the latest patches, jumping to build 00WW_2_22A with May 2018 security fixes. Just after that I decided to format the memory card: the phone proposed me just one choice: format as "portable memory".
Doing that I can't install apps on the sd card nor I can move them after they are installed on the internal storage (for the apps that enable to be stored on the sd card, of course....not the systems one I'm aware of). The SD card operates correctly for photos, music, file storage and so on.
The Nokia chat support confirmed me that the latest upgrade disables the option to use the SD card as a storage memory for the apps (that's why the format choice disappeared).
I hope that Nokia may consider in a future update to enable again the format choice so to permit SD Apps installation again.