i just faced this same issue today while working on a form validation coupled...

Contribution Date
Technology
Drupal
Contribution Project
Drupal core
Contribution Details

i just faced this same issue today while working on a form validation coupled with an ajax callback on Drupal 8. So it looks like D8 is still affected too.

Applied the Patch on #3 and now my validation code worked perfectly.

Contribution Author
georgekharmujai
Contribution Issue Link
If a custom beforeSubmit() or beforeSend() function on a Drupal.ajax object returns false, 'ajaxing' gets stuck as true
Contribution Link
https://www.drupal.org/project/drupal/issues/1907932#comment-12149759
Files count
0
Patches count
0