Pi-hole deleted blocked domains

General Customizing Pi-hole
1

When I went to bed last night, pi-hole was blocking 2.8 million domains.

Now it is blocking 1.8 million.

What happened?

2

I ran "Save and Update" under settings -> block lists and now I'm back up to 2.79mil domains blocked...... Not sure what happened here.

3

It could be that one of the sources of the lists was temporally down when the CRON scheduled update "pihole -g" was run.
So you didnt get all the domains as your used to.

EDIT: This bit in CRON:

pi@noads:~ $ cat /etc/cron.d/pihole
# Pi-hole: Update the ad sources once a week on Sunday at a random time in the
#          early morning. Download any updates from the adlists
11 4   * * 7   root    PATH="$PATH:/usr/local/bin/" pihole updateGravity

If you check the Pi-hole logs at the time the CRON job runs, you would probably see some more info.