To identify a connection issue with Instagram, I would first recommend verifying the network connectivity. If the Internet is working correctly and the problem continues, I would suggest looking into other applications on the same device to eliminate the possibility of device-specific network problems. If other applications are functioning normally, the next step would be to check for any pending updates for Instagram, as outdated applications may encounter issues. Additionally, clearing the cache data of the Instagram app could help resolve the problem. I would also advise checking for any software or hardware compatibility issues on the device. Uninstalling and then reinstalling Instagram might also help rectify the issue. Lastly, since the problem could sometimes be related to the server, I would look at Instagram's official social media accounts for any updates regarding outages. Overall, my diagnostic approach is systematic and comprehensive, ensuring that we examine and eliminate possibilities one step at a time.