No matter what I set the settings in Global Settings to on the fs4 it is not functional (tried setting it to all sorts of things, it is not working). Just bought the HX Stomp a month ago and did not back up anything. Perhaps restore to factory settings, update from there and see what happens. I play bass, so none of the new things in this update really mattered to me. It just messed up the fs4 on the footswitch...
EDIT: OK, I found out what us "footswitch" guys must do. Open HX Edit -> go to "File" (up left) -> preferences. Then choose "Device settings" and then set "Exp/FS Tip" to FS4 (it changed to EXP 1 with the update).