Steps to reproduce the issue

Go to Admin / Users / New and click the Save button without entering any form data.

Expected result

Form validation should prevent form submission.

Actual result

The form is submitted and returns with three Field Required messages.

System information (as much as possible)

J4 Nightly Build from April 27 2020 / Mac OSX/ Apache / PHP7.2

Additional comments

This problem affects most of the Admin components. Comparing with the Articles form it seems that most components use ToolbarHelper::apply('xxx.apply'); whilst the Articles component uses $toolbar = Toolbar::getInstance(); $apply = $toolbar->apply('article.apply'); The adjacent Save & Close button works correctly.