Thanks for being with Samsung and sharing your concern. We would like to inform you that if your SIM network supports 4G connection and also if it is only 4G SIM card in the device, it will connect to the highest available network available in the device. We would also request you to try different SIM cards in case the SIM network supports only 3G connection to check the issue and if the issue still persists, We would request you to provide logs/video within 15 minutes of issue occurrence by registering this feedback in Error Section (Samsung Members App -> Feedback -> Questions/Errors -> Create -> Error reports) so that your concern can be resolved soon. Be sure to hit ♡ when you find an answer that works for you. For Further assistance, you can get in touch with us via Live Chat option by following- http://livechat.support.samsung.com/Customer_new/IN. You can also connect us via Samsung Members web community by following mentioned url-https://community.samsungmembers.com/en_IN#/
