I was a bit shocked to find out my profile picture got somehow disappeared(?) in the other network. I checked on Stack Overflow, Meta Stack Overflow, Meta Stack Exchange and seems like only in Stack Overflow, it is correct.

This wasn't the case before, how did this happen? As far as I know, I have been using the same SSO login and email for all the sites. So Gravatar should show the same.

Here's a screenshot (with poorly hand-drawn red circles included):

not same

Here are the links for the same:

Is this a user error or a system error?