Auto Complete not working in multiple sessions?

[James Zukowski]

While testing an update to a panel, I opened the old version in one session and the new version in a second session on the same workstation. Whichever session I first access for the autocomplete seems to lock out the other session; it's still a multi-line, but doesn't create the auto-complete drop-down.
Is there something I'm missing/not setting up? Any suggestions welcome.