Thanks for the comments.
I had been transferring files using the SD card, putting files on the card with my PC, then inserting the card in ALP and then turning it on. But I recently saw another thread here that suggests having ALP turned on first before inserting the card, and that does seem to work better, usually.
Thanks also for the SyncToy suggestion. And that's also got me using the USB file transfer method now, (transferring the files from PC directly onto the card while in the reader) and that does have the new files showing up immediately in the menus, as advertised.
Summary: Guess I've been managing to always find the quirky way to do things with the ALP thus far
(And yes, it doesn't like to be stressed at all, patience helps.)