Filmstrip

When I browse and select my files I usually prefer FILMSTRIP mode and I've always had on the left the folders' panel to navigate into and in the main panel the file displayed enlarged and finally, in the bottom part, the panel showing thumbnails. In this set up the thumbnails in the bottom panel always schroll in orizontal direction by default.
In these last days I had to switch from vertical to horizontal direction showing, but now I can't modify this feature. Until today I 've changed the showing direction by the panel view/thumbnails. How can I fix this?
MacOS Sequioia 15.3
Bridge 15.0.2.432
MAc Book pro 13"