Irfanview 4.54, 64 bit, Windows 10 64 bit. And Windows 7 64 bit.
If I open a JPG file in Irfanview, I am able to move through the folder looking at/editing/saving the photos by using the keyboard arrows or the left/right arrow buttons in the tool bar.

With CR3 files in a folder, if I attempt to go to the next photo in the same way, The arrow buttons in the tool bar do not function (greyed out) and the keyboard arrows bring up the Browse SubFolders dialog box, instead of just opening the next photo.

To open the next CR3 photo, I need to close Irfanview and double click the next photo from the Windows file manager.

A missed setting on my end?
Thanks,
Matt