We have a SharePoint subsite which was created using No-Code Sandbox Solution. (Actually the site was created in SharePoint 2013, recently we migrated it into SharePoint 2019)
But the problem is, few document libraries in the site are having the type as 'List'. Please see the screenshot below.
Due to this (we suspect), the Document Library sync is not working. Even the 'modern ui' is not enabled.
My question:- Is there any way by which we can change the 'Type' ie SP.List.baseTemplate Property (list definition type) of the doc lib? Any suggestions are highly appreciable.