In some cases, trying to use an F4 search help in an SAP transaction via Personas would fail. The search help would return no values, and often the cancel button wouldn't work so there was no way out other than reloading the page and cancelling the transaction. There is a workaround for this, changing the settings in the "Help->Settings->F4 Help" dialog from "Systems defaults" to "Dialog (modal)":
This make search helps work properly, but is inconvenient as it is a per-user setting. A fix is now available in OSS Note 1885506, released today. The fix just forces dialog mode for Personas connections. I've been testing the fix for the last few days in my system and it has cured all of my search help problems. If you've been having problems with search helps via Personas, apply this note and see if it helps.
I'm mentioning this specifically as it is a fix to the ITS component and not to Personas directly, and so it doesn't show up in OSS searches for personas and so is easily missed.