This issue is not related to any JoomShaper product. Our products, including the frontend template and SP Page Builder, are designed specifically for frontend functionality and do not interfere with Joomla's administrator access. The problem you are experiencing may be due to a Joomla core issue or a configuration conflict.
I recommend checking Joomla's official documentation or seeking assistance from the Joomla forum, where the community can provide insights into potential causes and solutions. Additionally, verifying browser console errors and clearing cache/cookies may help identify the issue.
Thank you for your understanding.