I just opt-in into the PTC for the "Collect All"-option and the "Collect All" button is not there for me. Found this thread on reddit with screenshots https://www.reddit.com/r/oculus/comments/cmzbuw/how_do_i_collect_all_loot_boxes_in_oculus_home/
I'm on Rift CV1 and havent collected rewards for a year or so. Already tried restarting PC, restarting Oculus Software, and signing out and back into my account in the Oculus software.
I just hope your servers are ready for everyone pressing the Collect All button at the same time lol 😄 😄 😄