All downloads seem permanently Stalled, for 4 days now

[porphyry5]

What might cause qbittorrent to enter a permanently Stalled state on all downloads?

Since July 14 there is no change to the status of any of them, the number of Seeds and Peers never varies, and for downloads added since the 14th the number of both Seeds and Peers is fixed at 0, not a single one ever online.  But supposedly, one of these files has more than 60 seeds.

There is ample space on the drive to accomodate all these downloads.  If I try Force Recheck on any of these files it momentarily moves to the bottom of the list, then immediately returns to its original position and state

[porphyry5]

This is the most bizarre thing I've ever seen.  Eight days with 11 downloads stalled continuously.  Now just a couple of minutes ago I added a 12th torrent, and immediately 7 of them start downloading.