My Create & Edit list forms are rendering using the modern UI although we have customize them using Script Editor web part

Question

We have migrated 3 custom lists from SP 2013 to classic team site inside SP online, now the 3 lists have the following main settings:-

1. we have customized the list forms (Create & Edit) using Script Editor web parts, as follow:-

2. for the list settings >> we define to render based on the site settings (which is to use modern UI):-

so now the expected behaviour is that the list views will render using the modern UI + But when we create/edit the list items the Create & Edit forms will render using the classic experience. Now this is working as expected for 2 lists. but is failing for the third list.. where on the third list the Create & Edit forms will render using the modern UI, although they have customized the forms using script editor web parts.. any advice on this?

Answer 1

This article lists all features that will automatically switch to the classic experience.

Need to pay attention to this:

Only the first customization listed above will trigger a fallback to classic mode on the form.