Inconsistent output of serialized gutenberg acf block in post content

Hi,

I'm the author of https://github.com/pristas-peter/wp-graphql-gutenberg and https://github.com/pristas-peter/wp-graphql-gutenberg-acf plugins, which parse gutenberg blocks on post save and then generate the graphql schema for them.

I have started using acf blocks (pro), but have found bug, when the output of the block is saved differently to post content html when the block is edited and when it is not, which makes it difficult to use in my plugin.

Here is the example output of the same block when it is edited and when it is not:

<!-- wp:acf/banner-carousel {"id":"block_5ce074fe8acd9","name":"acf/banner-carousel","data":{"items_0_image":301,"_items_0_image":"field_5ce06b616c1fa","items_0_link":{"title":"Indexa","url":"https://google.com/","target":""},"_items_0_link":"field_5ce06c0b6c1fd","items_1_image":302,"_items_1_image":"field_5ce06b616c1fa","items_1_link":{"title":"Indexa","url":"https://google.com/","target":"_blank"},"_items_1_link":"field_5ce06c0b6c1fd","items_2_image":300,"_items_2_image":"field_5ce06b616c1fa","items_2_link":{"title":"Index","url":"https://google.com/","target":"_blank"},"_items_2_link":"field_5ce06c0b6c1fd","items":3,"_items":"field_5ce06b516c1f9","products":44,"_products":"field_5cf8c0ef0817d"},"mode":"edit"} /-->

<!-- wp:acf/banner-carousel {"id":"block_5ce074fe8acd9","name":"acf/banner-carousel","data":{"field_5ce06b516c1f9":{"row-0":{"field_5ce06b616c1fa":"301","field_5ce06c0b6c1fd":{"title":"Indexa","url":"https://google.com/","target":""}},"row-1":{"field_5ce06b616c1fa":"302","field_5ce06c0b6c1fd":{"title":"Indexaaaa","url":"https://google.com/","target":"_blank"}},"row-2":{"field_5ce06b616c1fa":"300","field_5ce06c0b6c1fd":{"title":"Index","url":"https://google.com/","target":"_blank"}}},"field_5cf8c0ef0817d":"44"},"mode":"edit"} /-->↵↵

Start by comparing the two serialized ACF block examples and reproducing the difference between an edited and an unedited block. Done means the block’s post-content serialization is consistent in both cases, but the issue does not name files, tests, or a specific implementation entry point.