I've got 2 identical Pi-hole installs and one doesn't update Adlists

2 Pi-hole - unbound instances running in docker containers on rpi 3b+s. Both are configured the same as far as I can tell. One of them updates the Adlist automatically weekly (both only have the default StevenBlack list installed) and the other does not update automatically or manually.

When I attempt to update Gravity manually on the instance that won't update I get " DNS resolution is currently unavailable" . The Pi-hole log shows "/opt/pihole/gravity.sh: line 332: echo: write error: Broken pipe" over and over.

Both instances appear to be working. I can run dig against both Pi-hole and unbound and get resolution.

I'm not sure why this might be and could use some assistance.

Please upload a debug log for the troubled Pi-hole instance and post just the token URL that is generated after the log is uploaded by running the following command from the Pi-hole host terminal:

pihole -d

or do it through the Web interface:

Tools > Generate Debug Log