Creating multipage pdfs with Elements has never been a real option.
Why not use an external solution based on 'virtual pdf drivers', which are virtual printers, such as the Microsoft 'Print to pdf' included in Windows 10 and available from many external sources for free or low prices? Just beware of some freewares which are not free of unwante ads...
The idea is that you don't 'save' a pdf, you 'print' a pdf... as a pdf file, with several selected files if you want.
For instance, you select your photo files as pages in the organizer or externally from the explorer and 'print' them as a single document.
Note that Elements can't save files in the common Acrobat pdf format (also used for Illustrator), it saves files in the 'photoshop pdf' format which is a file including the Acrobat format and the psd photoshop format.
Advantages: all the advantages of Acrobat pdf plus those of Photoshop (layers, text, shapes...) Opens directly in PSE without needing to rasterize the pdf. Recognized in the organizer, contrary to recent PSE versions which don't support the Acrobat pdf format.
Drawback: huge size.
The only limited way for PSE in recent versions to create true multipage Acrobat pdfs is in the Share by email option.