Question I can't mount a 128GB Micro SD card to my tablet

Jan 11, 2020
I am using a Lenovo Tab 4 10 + (TB-X704V, Android 7.1.1, System versionTBX704V_S000038_171219_ROW).

I currently have a 64GB Samsung Evo+ Micro SD card being used as internal storage (i.e. not portable) to supplement the tablet's 16GB stock storage. When I connect the tablet to a PC, the PC recognized the card (listed as Samsung SD Card) and I am able to transfer files back and forth through MTP. The card is also visible as internal storage via Settings>Storage and in my Astro File Manager application.

I recently purchased a 128GB SanDisk Ultra SD Card to replace the 64GB one.

When I insert the new card, I get the prompt to set it up. I format as internal storage and allow the process to complet. The card is then recognized by the tablet (SanDisk is visible in Settings>Storage). However, applications such as Astro File Manager, MX Player Pro, and Gallery Vault do not see it, and when I connect the tablet to the PC, it is not visible. If I set the card up as portable storage via the tablet, the card becomes visible to the PC Astro File Manager, but not MX Player Pro or Gallery Vault.

I have tried formatting the card to FAT32 using AOMEI but this has made no difference. I have also tried with a 128GB Samsung EVO+ Micro SD card but I have the same issues.

While the official specs state that the tablet can accomodate up to 128GB in expandable storage, I am unable to make it work.

Any help would be greatly appreciated.