A week ago I relisted 98 items using the bulk relister option, as auctions. When I got home from work tonight and checked my emails, I had 3 saying item sold, the rest were "your item has been relisted". There was nothing in the bulk relister to opt for relist 8 times for free. So, it must be automatic regardless of how you relist.

Sometimes if you relist each item manually, the relist box may not be there. Revise in a day or 2, and chances are it will have returned. If it doesn't, I have found it's there if you revise the listing in the app. Otherwise, clear out cookies and cache (using the for all time option) and see how that goes.