Can files from android internal be recovered after using adoptable storage? I have lenovo k50a40 which is pretty old. I was using my SD card as internal(adoptable storage). By mistake I took out my SD card with taking any backup and inserted another card. Now old card is not working and I have lost all my files. After trying available methods I came to conclusion that files on old card can't be recovered as its not encrypted.
Now what I'm thinking is, does android used to put all photos directly on SD card or first it goes into internal then its copied to SD card? If it first goes to internal then to SD then removed from internal then I think I can root my device and use a recovery app to recover the photos.
your only chance to get files back is decrypt MicroSD Card with correct encryption key. as long as you did not discarded the adoptable-storage by forgetting SD Card or factory reset, they key will remain on device.
therefore you can try to root your device.
be aware unlocking bootloader will erase all data.
you have two possible options:

get a temporary root shell with mtk-su, or

root your device (on locked bootloader) with SP Flash Tool and Magisk Manager


once you managed to access /data/misc/vold you can use linux dmsetup to decrypt your MicroSD Card and access the files
for more information refer to the adoptable-storage tag-wiki
How to decrypt Adopted Storage?