When using Navigation module, Save button doesn't trigger

I can confirm this problem.

I tried to reproduce this issue on Drupal 11.1.8 and PHP 8.3.10, on a clean install, but for me the button "Save and import" works fine on the feed add page.

Steps that I took:

1. Installed Drupal using the standard profile (via drush si).
2. Enabled modules "Navigation", "Feeds" and dependencies.
3. Added a feed type with the HTTP fetcher and the RSS/Atom parser.
4. Added mappings: "Title" to "Title (title)", "Item GUID" to "Feeds item (feeds_item): Item GUID", "Description" to "Body (body): Text".
5. Added a feed with title "Feeds" and feed URL " https://www.drupal.org/project/issues/rss/feeds → ".
6. Clicked "Save and import".

The import went fine and imported 50 items.

So I think this needs more steps for reproducing the issue, try to reproduce it on a clean install.

I also tried to reproduce the issue on Drupal 11.2.2, but I also did not encounter the reported issue with that version.

I was also using this Navigation Extra Tools → module.

Can you add that to your test bed?

Navigation Extra Tools doesn't make any difference for me. The button "Save and import" still works for me. Could it be theme related? Or are there perhaps JS errors on the page?