Does anyone have experience fixing an issue like this and what did you have to do to fit it?

Here is the issue: People send me offlines and I am not getting them when i login to my IM account. I have tested this and it is not a machine specific problem. I have tested this on 3 different machines and confirms that I don't get offlines. I have also confirmed that sending offlines to another IM account which I have is ok (I do get the offlines). Only seem to be an issue with one specific account. I've been researching this issue for last 3 days and just going in circles.

Any advice is welcome. Thank you!