Hello,
Today I switched to FLAC in Beatport Link, and I typically keep a bunch of music downloaded offline for instant access. Even when I removed them from my offline folder, re-downloading them would still default to the former setting (256kbps AAC). The same behavior for simply streaming it - it wouldn't stream the FLAC version.
The only solution here was to remove the track from my collection entirely, then find it again. I wanted to upgrade the sound quality of the tracks I'm already playing, not just new ones.
I feel this is probably just a minor oversight in workflow, not a "bug" per se.