Hi Max,
If you find that the 'flac+mp3' has not completed, it might be caused by a track name having a reverse single quote ` in the name. I had this problem with about 20 tracks, and when I edited the track name by replacing the reverse quote with the normal forward single quote ' then the compression continued. The reverse single quote character is value Hex 60, Decimal 96.
I logged this issue with Brennan Support in the post shown below a little while ago.
You can identify the problem track by opening up the B2 WebUI, then open up 'Settings & Status' window, then open 'Debug' window.
Then on the B2 front panel go to 'Settings' --> 'Compress Now' and select this.
The track name that the B2 is trying to compress will be shown in the debug window.
Regarding the 'Disk Used' figure, this might not be accurate. I have been looking at this issue and am about to post a query about this in a new thread to Brennan Support.
Regards,
Peter