All tables are wider than page text frame in PDF generated from DITA file

I customized the master pages in ChapterOutputTpl.fm (changed page size and text frame) and generated a PDF from my DITA book with the Publish command (after importing the customized ChapterOutputTpl.fm). The headers, footers, and main content of the PDF have the correct page layout; however, all of the tables extend into the (right) page margin. I have tried to resize the tables in the *.dita files, but they keep reverting to their default width when I reopen the file. I tried the solution in https://community.adobe.com/t5/framemaker-discussions/framemaker-dita-tables/m-p/10956885#M65232 but this did not work for me in FrameMaker 2020.

Can anyone help me with this?