I had similar problems with Smarty (which runs on the 3 network and has very similar settings). I used the settings from this site: https://kenstechtips.com/index.php/mobile-internet-apn-settings#Three which was the only one that mentioned the proxy configuration for Smarty… After that I was finally able to send and receive MMS on my XA2( Dual Sim). I can see you have IP configuration only for the protocol, I would switch it to Dual and restart the phone just in case… Hope you fix it soon…