You are overwriting the input fields in the panels when the user clicks on the button ('Data settings', 'Message settings', etc.) in the Cellular & Data main panel. IHMO this is not needed because the at this point the sub panel is already built (the APN list is built, one item is preselected and the setting fields are filled). I see your intention is to load the settings stored under the `ril.data.apnSettings` key, but the APN already preselected is actually the one (best match) to be used. Please, remove the code introduced above. The idea would be to build the `ril.data.apnSettings` setting with the settings from the APN selected by the user (or the preselected one if the user doesn't choose another one).