iProcurement autocomplete/autovalidate LOV not opening

We have one user for whom the autovalidate functionality on a couple of iProceument fields (Project, Task, etc.) that have LOVs is not working.  When she enters a partial value and then presses the Tab key, the LOV does not open.  She is, however, able to click the flashlight to manually open the LOV and enter partial search criteria there.  I am not able to replicate the problem in our Development environments, and am not sure how to proceed.

We are running OA Framework version 11.5.10.6 and OA Extension 9.0.3.8.13.

The user is running  Java 7, update 67 on IE 11 (but other users with the same setup are not having the problem).