Hi there!
Sorry to hear that.
From which environment you are exporting the SPPB page, please? Let me know the version of SPPB of the both sites.
Notice! You can reuse exported pages also on different websites, but you have to be sure that it contains the same list of addons and image structure. If not, part of the content may not work. Exported .json file does not contain any addon code inside, only layout and page settings. Also, you need to have the same images stored in the new destination to get the visuals.
You will find this notice in the documentation too:
https://www.joomshaper.com/documentation/sp-page-builder/export-import-and-save-for-later-use
Best Regards