Hi Derek,
Thank you for providing the detailed troubleshooting information.
Based on your description, the issue occurs consistently across multiple browsers and even different operating systems. Since you've already cleared the browser cache and cookies, restarted the device, and tested with another browser, this appears more likely to be a service-side issue affecting Sway rather than a problem with your local browser or device.
Additionally, there have been reports from other users experiencing similar Sway errors and unexpected page refreshes. While this may indicate a broader service issue, I cannot confirm whether there is an official incident or provide an estimated resolution time unless it is communicated through Microsoft's service health channels.
For reference, you may review the following service monitoring sites:
This link is shared by community members for your convenience. It points to a third-party site that is not managed or verified by Microsoft. I can’t guarantee the quality, safety, or suitability of any content or software found there. Please review carefully and make sure you understand any potential risks before using it.
If you have administrator access to your tenant, I recommend signing in to the Microsoft 365 Admin Center and opening a support request by selecting Help & Support in the upper-right corner of the page. This will allow Microsoft Support to investigate the issue further using backend diagnostics and service logs. If you do not have administrator permissions, please contact your organization's IT administrator and ask them to open the support ticket on your behalf.
They can follow steps from this link: Get support - Microsoft 365 admin | Microsoft Learn
In case you do not know who is your IT admin, kindly refer to this article: How do I find my Microsoft 365 admin? - Microsoft Support

In the meantime, I recommend avoiding significant edits in Sway, where possible, as the repeated page refreshes may cause recent changes not to be saved successfully.
I hope this information helps. If you have any questions or concerns, please let me know, and I'll be happy to assist further.
Kind regards.