`schedule event at` when chained behaves oddly

These are the times for the bofm:verse_needed event:

2021-03-08T22:36:33.951
2021-03-08T22:37:34.351
2021-03-08T22:38:34.751
2021-03-08T22:39:35.162
2021-03-08T22:40:35.545
2021-03-08T22:41:35.967
2021-03-08T22:42:36.373
2021-03-08T22:43:36.788
2021-03-08T22:44:37.188
2021-03-08T22:45:37.570
2021-03-08T22:46:37.973
2021-03-08T22:47:38.409
2021-03-08T22:48:38.795
2021-03-08T22:49:39.311
2021-03-08T22:50:39.688
2021-03-08T22:51:40.069
2021-03-08T22:52:40.456
2021-03-08T22:53:40.828
2021-03-08T23:27:38.030
2021-03-09T00:10:07.829
2021-03-09T00:11:08.418
2021-03-09T00:12:08.807

Where the code is

  rule bofm_verse_needed {
    select when bofm verse_needed
    pre {
      v = bofm:verse();
    }
    fired {
      raise bofm event "schedule_bump";
      raise bofm event "verse_to_route" attributes v;
    }
  }
  rule bofm_schedule_bump {
    select when bofm schedule_bump
    fired {
      schedule bofm event "verse_needed" at time:add(time:now(), {"minutes": ent:minutes})
        setting(schedule_id);
      ent:schedule_id := schedule_id;
    }
  }

Notice that it stopped and then started again, twice. How does this happen?

ent:minutes is set to 1 and left unchanged throughout