Sharepoint Online Deployment

Good morning,

Does anyone have tips on deploying a course to SharePoint Online? Our company recently moved from SharePoint 2010 to Online. In SharePoint 2010, we were able to upload as HTML files and launch with no issue. At my previous company, when we moved to SharePoint online, we converted the Lectora course files to .ASPX and added the HTML extension ASP. NET to the title level and all was well. However, with this move, converting to .ASPX isn't making a difference. Clicking on the index.aspx link (or copying/launching it) results in a Save-or-Download dialogue box.

Has anyone come across this issue recently? I'm on Lectora Version 18.2.1.

Note: I did find this topic, which is essentially the same issue, but with the move to SharePoint Online the solutions listed aren't working.