Ok, my next payment just came in and went to the multiout reverse tab, as expected.
I can confirmed that this payment and all previous one have been added up to my balance so everything is ok.

Conclusion: Do not panic is you see your payments going to the multiout reverse tab; this is the way thing works now and those payments are added to your total balance as it should be, of course.

I hope that will help. Thanks.

All right Guys. I'm going to wait for my next payment and going to care take of my balance if it grows or not. I will definitively put a conclusion here after this verification, to help everybody understand how the new payment system works.
Thanks to twice of you for the clarifications.

Hello to All. I adress this message to the cryptoguru's pool admin; I was not able to find on the pool or on some burst forum pages who contact about this pool so I post this message here.
Dear Admin, I would like to understand why all my mining payments are systematically reversed (2 so far) so they 're not credited to my balance ? The concerned adress: 9UJL-LPZC-YSCK-DKQD3.

Thanks for your attention and help; it would be a good thing to found a permanent solution to the problem to avoid me or others to come back each time we receive a reversed payment cause I've found, exploring random accounts, that it's not an isolated case. Peace.