opkg update
similar to this:
Downloading http://downloads.openwrt.org/releases/19.07-SNAPSHOT/packages/mipsel_24kc/telephony/Packages.gz
*** Failed to download the package list from http://downloads.openwrt.org/releases/19.07-SNAPSHOT/packages/mipsel_24kc/telephony/Packages.gz
Channel auto doesn't automatically do anything. There is no reason to use that setting. Always explicitly set a channel which makes sense with respect to regulations and neighboring systems. Also always set your country.
ACS still doesn't do anything sensible on OpenWrt. All it does is selecting the first legal channel allowed by your wlan card, it doesn't check which channels are free, it doesn't react dynamically, it's not even supported by all wlan drivers in the first place. It has a very narrow use case, but effectively it boils down to "don't use it".