I got it!
If you already spent lots of gems you need to do a "fuzzy search" (the magnifying glass with the question mark next to it)
it will do a big search, and then each time you acquire gems (this one only works when acquiring gems) type how many you got and click N=O+D and it will narrow the search, keep doing it until one left. (the value should correlate total amount of gems you've ever received)
Do the same steps as the guide, but when entering your amount make sure it is how much you want MORE than the amount it says you've received. (so if you want 200k and it says you've received 50k, put 250k and you'll get 200k)