Thanks for your message. We’ve investigated the issue with GenerateBlocks and found that the issue happens because GenerateBlocks loads styles dynamically according to the post/page loaded. Therefore, since we only load the content of the popup in another page/post where the popup is shown, the styles from GenerateBlocks for the blocks in the popup are missing. Only the ones for the page/post that hosts the popup are included.
In fact, we found that this problem may already happen with particular styles of core blocks from WordPress or any other block plugin that loads scripts/styles dynamically. For example, the horizontal centering of the core/buttons
block in Gutenberg occurs because the block editor generates a dynamic CSS style that is loaded only in the page/post where the buttons block appear. A core/buttons
block with centering styles in the popup will appear as not centered when it appears in the frontend. Exactly the same issue that you discovered with GenerateBlocks.
We have a solution to fix this issue with the missing styles/scripts required by any block included in a popup. Right now, we are developing it and testing it internally. If it works as we expect it should and it fixes the issue with the missing styles (we hope it will), we will release a new version of Nelio Popups soon.
I’ll keep you posted. Hopefully we will overcome the issue quickly. Thanks again for helping us noticing it.