Steps to reproduce issue:
1) Open chatter in PC and in ipad/iphone. (Any oddo version)
2) Type messages in PC. You will get messages in iphone.
3) Lock the Iphone.
4) Type messages in PC.
5) Unlock iphone. You will not get messages in iphone. You will get messages in iphone until device is unlocked. After locking it will not sync messages. You will need to reload page to get new messages.
But the same behavior works fine with android devices!! Only in the iphone this is not working.