I think he's referring to browsing skills mods in your inventory. On ps4, the L2 button is overloaded to both mark an item as junk, as well as toggle between browsing individual mods or mod categories.
So as soon as you mark an item as junk, you start jumping categories, and have to either unmark the item, or mark a second item to return to individual browsing.
Do you still need a video? Anyone on PS4 (Pro) can reproduce this I guess?
It's indeed especially noticeable when you try to "clean up" the mods and start marking for deletion.
Then it just becomes hard to navigate through the menu.
WORKAROUND:
The workaround now is that I transfer the modes I want to delete to my stash and there I can easily mark as junk and then bulk delete
Yup, can confirm the same thing. List works fine until you mark one of the items as junk then when you go up and down it jumps between the each skill type instead of each mod item in the list. Very annoying.
Although I have found if you just deconstruct a mod without marking it as junk it still works normally. Teadious, but a workaround for now.