Poor downloads

Hi you have had a couple of answers which are all good however if you had three on your dual sim phone and the smarty sim is replacing another network try resetting your network settings. It will delete all connection info including any Wi-Fi connections you have and you will go through your phones operating system setup for dual sim but it maybe that clearing out old network data will allow the smarty sim to forced a clean settings update. It’s a long shot but it might just help depending on what phone it is