It appears that you have the same default sources that I do. When I refresh in GL GUI, I get:
“Failed to update repository list, please check your network and try again.”

When I attempt to Update lists… in Luci I get:

Executing package manager

Downloading https://fw.gl-inet.com/releases/v21.02.3/kmod-4.2.1/aarch64_cortex-a53/mediatek/mt7981/Packages.gz
*** Failed to download the package list from https://fw.gl-inet.com/releases/v21.02.3/kmod-4.2.1/aarch64_cortex-a53/mediatek/mt7981/Packages.gz

Downloading https://fw.gl-inet.com/releases/v21.02.3/packages-4.0/aarch64_cortex-a53/glinet/Packages.gz
*** Failed to download the package list from https://fw.gl-inet.com/releases/v21.02.3/packages-4.0/aarch64_cortex-a53/glinet/Packages.gz

Downloading https://fw.gl-inet.com/releases/v21.02.3/packages-4.0/aarch64_cortex-a53/packages/Packages.gz
*** Failed to download the package list from https://fw.gl-inet.com/releases/v21.02.3/packages-4.0/aarch64_cortex-a53/packages/Packages.gz

Updating database.
Database update completed.

Errors

Failed to send request: Operation not permitted
Failed to send request: Operation not permitted
Failed to send request: Operation not permitted
Collected errors:
 * opkg_download: Failed to download https://fw.gl-inet.com/releases/v21.02.3/kmod-4.2.1/aarch64_cortex-a53/mediatek/mt7981/Packages.gz, wget returned 4.
 * opkg_download: Check your network settings and connectivity.

 * opkg_download: Failed to download https://fw.gl-inet.com/releases/v21.02.3/packages-4.0/aarch64_cortex-a53/glinet/Packages.gz, wget returned 4.
 * opkg_download: Check your network settings and connectivity.

 * opkg_download: Failed to download https://fw.gl-inet.com/releases/v21.02.3/packages-4.0/aarch64_cortex-a53/packages/Packages.gz, wget returned 4.
 * opkg_download: Check your network settings and connectivity.

The opkg update command failed with code 3.

What am I missing? I was expecting you may have added custom sources, but it does not seem so.