Macbook Pro 10.14.6 mScecure 5 installed and working properly
New Macbook Air mSecure 5 not installed yet
New Used 27" iMac 10.14.6 mScecure 5 installed and working properly
Two very old iPads iOS 9.3.6 mScecure 5 installed and working properly
Two iPhone 6 iSO 12.5.2 mScecure5 installed, but does NOT sync properly
Thank you for contacting us, and I'm sorry for the issue you are experiencing. I'm not sure what could be causing this to happen, but we'll get everything working correctly on all your devices. Real quick, I just want to make sure I understand correctly that four of your devices are working correctly. Your MacBook Pro, iMac and two iPads are all working correctly, which means that they all show 279 total records, correct? On Mac, you should see that number next to "All Items" at the top of the left column, and on iOS, you will see that number next to "All Items" at the top of the menu after tapping the menu icon in the top left of the app. Are you seeing 279 in those locations on those four devices? Also,the two iPhones, are you seeing 104 in next to "All Items" at the top of the menu?
What I'm going to have you do next is test the syncing on all six devices. Please locate a record that is common in all six mSecure apps. After you find the record, lock mSecure on all devices but your main Mac. Now edit the record on your main Mac and add a hyphen to the end of the record's title, then save the change. Wait for about 10 seconds, then open and unlock mSecure on all the other devices. Does a sync take place in all the apps, and do they all now have a hyphen at the end of the record's title?