Hello Kare Casals,
Thank you for reaching out to our technical support forum. I’m sorry to hear about the trouble you’re experiencing. Rest assured, I will look into this issue for you and work to resolve it as quickly as possible.
Content of SPPB addons from articles is stored in SPPB tables, not inside the article content table. So, if you switch back to Joomla article, Joomla editor content will be shown. Similar things will happen when you turn off SP Page Builder article integration.
For more details:
SP Page Builder Article Integration
Best regards