R4 SDHC Dual Core 2016 (r4isdhc.com (not sure))

[123321mario]

Hello, I don't really know if my cart is legit or not, I lost the label but it looked exactly the same as the one below, just i'm unsure about the website.

I installed NTRBoot last year to install CFW on some 3DS but now I want to bring back my flashcart to stock firmware to play games with it. But there's a problem : Every flashcart in the menu says that my card is not supported. I use the last version.

Images (Click to Expand)

Front (what it looked like with the label, replace 2017 by 2016) :

Back of the cartridge (front is plain white since i've lost the label) :

Back :

Front :

GM9 Untrimmed Dump: (I don't know what that is)
There's the backup i've made while installing NTRBoot :
backup.zip

And there's the log, set to DEBUG level :
ntrboot.log

I hope someone can help me