Since I think the UI7 update the horizontal scrolling was locked out and only vertical scrolling could be done. Unless one was prepared to carry out a manual sort of your app icons in custom search. Today I found a solution on Reddit titled "I Got The Horizontal App Draw In Alphabetical Order In New UI" by JustHano under the subject r/samsung
JustHano suggested this and it worked for me.
"Open your App Draw and Press the three dots next to the search bar.
Sort it by custom.
Make a folder with the first two Alphabetical Apps.
Click the plus in the folder and add all your apps.
Press the three dots again and sort by Alphabetical then switch it back to custom (might not be needed but just in case.)
Delete the folder while in custom sort and all the apps will come out in Alphabetical order."
Not sure if we are allowed to share the link so you can thank him.
