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.