I've seen posts about this elsewhere, but I believe reigniting the conversation around this bug is especially important now that it seems like the Le Monarque specifically drops when completing a frame with a much higher chance from powerful frames. I had completed all of my available powerful frames on my Hunter (the intro bow you get from repairing the Izanami forge and then the bow and the pulse that Ada sells) and then proceeded onto my Titan. I had to unlock the Gofannon forge (which gave me my intro Sniper frame) and then the Izanami (which gave me the intro Bow frame) and completed the weekly powerful armor that Ada offers. When I got back to Ada, not only did she NOT have the Powerful bow and pulse frames that I haven't done, but she also only had the non-powerful bow; no pulse in sight. This wouldn't have been that frustrating before, as I'm already very close to 650 and already have good rolls on my hunter, BUT since this most likely means I just missed out on my remaining 2 chances for Le Monarque, I'm quite upset to put it nicely. I'm still going to farm the non-powerful bow frames on my hunter, but from what I've heard it is MUCH less likely to be obtained from those.