1. This is a configuration issue. Did you use the GL UI Wireguard client page to configure? Or manually via config files?
  2. To disable roaming run the command AT+QCFG="roamservice" 1 to enable it again AT+QCFG="roamservice" 2 or automatic AT+QCFG="roamservice" 255
  3. This is also a series of commands, i don’t know exactly which. @wellnw @robotluo can you help with this?
  4. To backup your config, follow the instructions here how to install the advanced menu:
    More Settings - GL.iNet Docs

Then after login into Luci (the advanced menu for OpenWRT), backup is under “System → Backup / Flash Firmware”