I am using SKSE, I backed up some saved games for cleaning out my saved game folder. I then reopened the game and this save does not show up in my game

Save 2126 - Vaako Volkihar Keep 89.11.02 - Copy.skse

I notice some of my saves are .ess, most all of them are skse now. It doesn't make any sense to me, but if anyone could help I would appreacite it.

The .skse files are co-saves where SKSE stores some information on the actual saves. The actual saves end in .ess. The game only recognizes ESS files as saves.