USB2 not recognized by Mosaic App

I’ve been trying the Mosaic App, all works well (Tidal/Qobuz, Podcasts, Radio) but selecting USB on the app, with a SanDiskSSD drive containing PCM music files attached to USB2, Mosaic now says “Nothing Found.” Mosaic could access the drive before without problem. Can’t think of any changes/reasons for this.
I have tried 2 different SanDisk SSD drives, reformatting (MSDOS-FAT 32), re-copying the files, to no avail. Power-cycling the Vivaldi One and the iPad with the App, as well as my router, do not help. The drives play fine on my computer when attached to either of its USB2 ports.
Factory-reset of Vivaldi One (with subsequent reconfiguring of my original DSD, filter, etc. settings) did not solve the issue.
Unless I’m dealing with 2 drives that somehow are not recognized by the Vivaldi but by the computer, could this suggest an issue with the USB2 input?
Any suggestions?

My guess is your SanDiskSSD is drawing more power than the Vivaldi One will support. If you Google search your SanDiskSSD, looks like it can draw as much as 2.7-2.9A.

The limit according to the Vivaldi One Manual is 2.1A;

Your are correct. I am now using a simpler, lower-power-requiring SSD, and all’s back to normal!
Thank You!