I have a daily scheduled task with ...
  SCHEDULED: <2019-01-11 Fri 07:50 .+1d>

Recently, when I complete the task it not only moves the schedule to the
next day
... but it also /_rewrites_/ all of the "Rescheduled from ..." entries
in the LOGBOOK.

For example,
  - Rescheduled from "[2019-01-11 Fri 07:50 .+1d]" on [2019-01-02 Wed 10:54]
  - Rescheduled from "[2019-01-11 Fri 07:50 .+1d]" on [2018-12-31 Mon 11:50]
  - Rescheduled from "[2019-01-11 Fri 07:50 .+1d]" on [2018-12-16 Sun 19:29]
  - Rescheduled from "[2019-01-11 Fri 07:50 .+1d]" on [2018-12-03 Mon 10:49]
 etc.

Those previous LOGBOOK entries no longer are available; they are wiped
out by new task completions.