Mobile data can't connect (with exclamation mark) but wifi

My phone is Motorola XT1033 dual-SIM (Lollipop 5.1) * have active mobile-data internet packages * can connect and open provider's website (to check package status & quota) * valid APN settings (at least following provider's instructions) There is a problem on mobile-data connection, see the differences here: **Data ON, Wi-fi OFF** * there is an exclamation mark on the mobile-data signal bar * NOT connected to internet (even the signal is H) **Data ON, Wi-fi ON** * there is NO exclamation mark on the mobile-data signal bar * connected to internet What I've tried so far * rebooting my phone * turn mobile-data off and back on * re-attach the SIM card * install my SIM card to another handset (can't connect to internet) * install another SIM card to mine (can connect to internet) Does anyone have the same problem? I'm looking forward for the solution.