Is there a Gachapon trick?

This makes me wonder if there's a trick as well. I used 8 tix at Hene and still didn't get the chair, even though I have hella Set-Up space available. WTH am I doing wrong? Why!!!

I bought 7 tickets with my spare NX and tried for the chair. I just got low level archer crap until my last ticket I got a racoon mask. So that made up for it. I guess that statement about increasing the gach rate for rare items was true after all.