Minecraft Bedrock Multiplayer Connection Issue on iPhone Using Mobile Data

I am experiencing a Minecraft Bedrock multiplayer issue on iPhone using Telkomsel mobile data in Indonesia. I can access public servers and the Marketplace using mobile data, but I cannot join my friend’s world. I suddenly get disconnected with the error “Disconnected due to the server being unavailable” (error code: Boat). Afterward, my friend still appears online, but the Join option disappears. Joining the same world works normally over Wi-Fi. Mobile data also worked earlier that day. Please investigate whether this issue is related to mobile network compatibility or multiplayer connectivity. Thank you.