Runes of Magic US / AU

Two days in a row, I got NO [Phirius Shell] after successfully running the Goblin Minigame
I used to get 50x[Phirius Shell] during a successfully run. My loot from the chests still includes:

1x[Master's Simple Repair Hammer]
2x[Goblin Champion Badge]
3x[Arcane Transmutor Charge]
... but No [Phirius Shell]

Everybody else in my party gets their normal 50x[Phirius Shell] ... but I do not
Running as Level 59 Rogue / 55 Scout not carrying any [Phirius Shell] in backpack,
with several open spots in backpack. No error/warning messages seen.

Is/Has anybody else experienced this problem?
Can you suggest something that I might do differently?

** ANSWER ** There is a 1000x[Phirius Shell] MAXIMUM.
This INCLUDES all [Phirius Shell] in your backpack, bank and elsewhere. Another
symptom is receiving less then 50x[Phirius Shell] after a successful Gobs run.

Quoted from "vfwiffo;539925"

The only time I ever not gotten any was when I was at a max. But there was a message associated with it telling me that I reached max. I take it, other sources of shells are acting OK.

I did not get any message about max. What is max? I was not carrying any​ [Phirius Shell]
in my backpack, which had several open spots. Does MAX include what I have in my bank?

Quoted from "wggp;539935"

You have to be at least level 50 also I beleive, so if you switched classes and it is not 50 you will not get[Phirius Shell] .

I am aware of the Level 50 minimum. However, both time I was running
Level 59 Rogue / 55 Scout

Quoted from "vfwiffo;539969"

Yes, Max is 1000 and it does include the ones stored out of your backpack. I would say "less than 50" explanation is more viable and fits the symptoms better. While you were over 50, for whatever reason the system decided you are not.

I believe you have the correct answer. Thank you for your help
Now I have to figure out the best place to spend my 1000x[Phirius Shell] - any suggestions?