I've been trying to overcome this available storage issue too
, it's the p8 lite 2017 for my daughter.
But also same error: "Adoptable storage not available on device with native FBE"
Running july 2018 firmware PRALX1C432B370.
Reading Huawei community, it's a Huawei choice.
Found in: https://uk.community.huawei.com/smar...24/index1.html
We recommend that you set the SD card as your Default Storage (Settings > Memory and storage > Default location: SD Card). This will save the photos and videos you take on the SD card.
Applications cannot be moved to the SD, for security reasons.
Default storage means the default storage for the camera to store all photos and videos taken, you cannot move across any apps you have downloaded to the memory card to free up space on the device.
I think it's related to the EMUI8. I read posts mentioning it was allowed at least in EMUI5.1
I guess, it's better not buy Huawei with EMUI8 !!
or see a way to get a custom ROM.