I reported this copy below of my design to Maker World and they came back saying they can not see that this is a copy of my original design - I designed it with Tinkercad and made an error with my layout resulting in the misalignment with the two surfaces meeting on the side. Circled in red.
I think it does look like it qualifies as a “remix” and would hope the other creator would give you credit for the original design. This is just proper creator “etiquette”.
But you also published it as Creative Commons CC0 which means they are technically not obligated to give you credit.
“No Rights Reserved”
CC0 enables scientists, educators, artists and other creators and owners of copyright- or database-protected content to waive those interests in their works and thereby place them as completely as possible in the public domain, so that others may freely build upon, enhance and reuse the works for any purposes without restriction under copyright or database law.