What is your firmware version? Compile time?

I am testing on AXT1800 which may be different.

But your opkg links are not correct. This is mine.

root@GL-AXT1800:~# opkg update
Downloading https://fw.gl-inet.com/releases/v21.02-SNAPSHOT/kmod-4.0.1/arm_cortex-a7/ip60xx/Packages.gz
Updated list of available packages in /var/opkg-lists/glinet_core
Downloading https://fw.gl-inet.com/releases/v21.02-SNAPSHOT/packages-4.0.1/arm_cortex-a7/glinet/Packages.gz
Updated list of available packages in /var/opkg-lists/glinet_gli_pub
Downloading https://fw.gl-inet.com/releases/v21.02-SNAPSHOT/packages-4.0/arm_cortex-a7/packages/Packages.gz
Updated list of available packages in /var/opkg-lists/opnwrt_packages
Updating database.
Database update completed.