Formatted SD Card as internal storage, now facing major storage issues

I recently bought an Intenso microSDXC UHS-I Premium card, formatted it as internal storage, and the content has been moved without any errors. But after that, the phone started having several issues: - Most photos, videos, music, and recorded audio files are missing. - Some apps—like CamScanner, Foxit PDF Reader, and the camera—don’t work. - WhatsApp media (voices, images, videos) can’t be downloaded or saved. - App updates can’t be installed. - Storage shows a negative value (see attached photo). I’ve tried common fixes online and contacted the manufacturers, but nothing has worked. I also couldn’t find an option to reformat or separate the internal storage from the SD card. What would be the best next step? Should I try reinserting the SD card and choosing "forget" option, enable “Force allow apps on external” in Developer Options, or is there a better solution to recover the files and resolve the storage issues? - Device Name: Redmi Note 9 Pro - MIUI version: MIUI Global 12.0.3 Stable 12.0.3.0(QJZMIXM) - Android version: 10 QKQ1.191215.002