I have transcoding enabled in navidrome and tempus..it was all good for the past year, but today I got this warning that I consumed all my data plan. I listened to one hour of my music and just like that, bam, 17GB gone.
Not my lucky day I guess.
Even maxed-out FLAC won’t use anything like 17GB in an hour; doesn’t seem like a transcoding issue.
Are you sure you didn’t accidentally hit an option to download your library locally to your phone?