Synced Contacts getting lost from Phone only.

I keep all my contacts synced with Google account.
And since a month (not sure the exact time), I can see contacts (specially the numbers) are being lost from my device. Can anyone tell me why this is happening?
- This is happening frequently.
- But if I go to Google Contacts, I can still see my contacts intact.
- Google+ part of the contacts are unharmed (as I have Google+ app and chose to show up the circles in my contact book).
- If I create another contact with the same name from the device, and go to Google contacts on the web and merge the duplicates, I get back the contact into my device back.
- I don't have a second device to sync with.
- I haven't seen this happening with the same contact twice "yet".
- I have 2 Google accounts but I keep all the contacts into one account only.

Note: I'll keep "Removing Google Account and reattaching them" as a last resort.