Hello, the Android Operating System is as complicated as any other, it has its advantages and its disadvantages, but it is definitely good, I send you a video that has several alternatives to solve that problem and I hope so.
By the way, if you want to change the ROM you must choose an appropriate one that doesn't have complications, I can also leave a link, but if you are not sure or do not know how to do it ... don't do it.
Hello Charmaine, I think it is a good cell phone, having the Android Operating System I hope that the video I show you can adjust to the configuration of your cell phone, if not, please let me know I'm not familiar with this brand. For some reason that sometimes we don't know the function that synchronizes different elements stops doing it, maybe some update or something like that, then we must erase that memory defect and restart the function as new, but don't worry that almost everything has a solution in this field.
Hello, Admire this problem can happen from time to time, for example, it stops synchronizing when being out of range of the receiving device, the application that synchronizes stops, etc. We must have enabled this application that works in the background (very important) I leave a video as a better example.
Hello Mark, this happens for several reasons:
-The contacts are stored on your SIM card and you remove that card for another phone.
-You use the contacts in your Google account and I log out of the account in your phone.
-Make a Factory Reset and saved your contacts in the internal memory of your phone.
I recommend a video to help you fix it.