New version 3.2 / Thunderbird v121 Beta not displaying some folders in folder pane

Edited the manifest and 3.2 ran OK with TB beta v120.  TB beta v121 now released so again edited manifest.json to allow v121 to run.  Add-on loads but folder pane does not show Local Folders and only the header for other accounts.  The folder list for the account does not display when the header for the account is clicked.