Hi. I've seen a bug report below from late March regarding Charles's skills not working. I believe it is a more general bug with Detect Secrets, and possibly with all extra loot skills. Interestingly, those skills WERE working properly for me at the time of the other bug report, but stopped working sometime between the Mar31-Apr2 raid and the Apr 7-9 raid.
In the previous week's raid, Mar 31-Apr2, my Charles + 3x raid bonus people + additional detect secrets item team would bring back 120-150 raid items. In the most recent raid, Apr 7-9, my Charles + 3x raid bonus people + additional detect secrets item team would be bringing back 75-85 items, same as months ago when I didn't have Charles or Detect Secrets items.
My other teams with scavenger and/or treasure hunter items also appeared to be bringing back reduced quantities as well, equivalent to what I used to bring back months ago before I got extra loot skill items, but I can't quantify that very well.
This was consistent throughout the entire raid, so not just a one-off RNG issue.
In a related note, running lvl 1 Primal Horn yesterday, which should give me 1-1 base, with 1x detect secrets and 1x Treasure Hunter II item (Charles not in group), I got 5 items on my Treasure Hunter person, and 1 item on everyone else, which I believe proves that Detect Secrets (and possibly scavenger) is not working. I'm running it again and will try to link screenshots once it completes in about 6 hrs.