I made a long post about my problems with my nokia 5 when using an sd card as internal storage and how customer support treated me as if it was android 8.1 instead of 9.0 and how it was in the end completely useless so I will not repeat it here, I`ll just paste a link to that here:https://community.phones.nokia.com/discussion/42410/sd-card-problem-and-terrible-customer-support#latest
I tried to put it as link, but then this post never got posted.
Ok the TLDR is third party file managers and pc can only see the small internal storage and not the sd card
set as internal storage and vice versa, and apparently customer support has no idea why and say that setting an sd card as internal storage is not even supported which is a lie.
After checking again my phone, the one recognized was the small internal storage again, so it passed from internal to sd and back to internal again and I had no idea why, but it is very simple.
Back in 8.1 when you set an sd card as internal storage android merged the 2 memories into 1 big logical unit, but 9.0 treats it as 2.
But if a third party app like a file manager or the pc tries to see the storage, only one is visible, and this is by design.
Only one of the storages has the ``flag´´ to be visible to other apps or the pc and one remains hidden and the way to choose wich one is visible is to migrate data there, let me explain.
You can have apps in both storages and put change them whenever you want, but migrate data is not that, is like 300 to 500mb that includes the flag that tells the system which storage is visible to third party file managers and the pc and changing it takes like a minute.
So for those who want to use an SD Card as internal storage and be able to transfer files with a file manager or the pc here are the instructions:
1)Set you sd card as internal storage.
2)Transfer apps to it or do whatever you want.
3)In settings go to storage and then select either the internal or the sd card depending on which you want to make visible to the file manager/pc.
4)Press the 3 vertical dots in the upper right corner.
5)If there is an option that says migrate data select it and then select move content, wait for it to finish and you are done. If there is no migrate data option, it means that the selected storage already has the flag and is visible to file managers and the pc.
If you need pictures, comment and I`ll post them.
Also comment if this helped you.