I want to go back to a previous version of the homepage of a document set content type in a specific document library called "Reklamationen". The content type is called "Reklamation". I couldn't find the file in the document library. It is also hard to find files there because it has over 100.000 files stored in it. It is also not in the SiteAssets in the site contents. This is all in classic UI.
Not sure if this is the same for SP Online, but for SP 2016, the Doc Set home page is in a folder named after the content type, inside the document library's hidden "Forms" folder.
So if SP Online works the same, your Doc Set home page would be in
I don't know exactly how you would go about reverting to a previous version (Powershell?), but that's where I think you will find it.