Gutemberg block not work well in single product

Hello. Why if I add a single HTML block to a WoodMart product article, the text goes below with Gutenberg blocks https://www.montearancio.com/prodotto/cinturino-per-orologio-in-pelle-classic-marrone/ while if I view the same block without putting it in the article it’s fine? https://www.montearancio.com/?cms_block=cinturinoclassic

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