Hmm. The connection is definitely being closed by the PLC, not by Ignition. I’m not really sure why, however. It does look like it attempts to reconnect though.
You might try upgrading to the latest 7.6.3 release candidate, which contains a few fixes to the the CLX driver, among other things, that were ported from the 7.5.x branch after 7.6.1 was released.
You might also check out the status page for that CompactLogix device and see how many unconnected and CIP connections are used and how many are allowed.