Inconsistent Logout Behavior on Multisite

I have 3 different multisite instances, and the logout behavior works differently on each site when WPS Hide Login is active:

On one site (hosted on Ubuntu 22.04 with PHP 8.1), it works as expected. Clicking the “Log Out” link logs you out without issue.

On the second (hosted on Pantheon with PHP 8.3), clicking on the “Log Out” link _does_ log you out, but you get the “You are attempting to log out of [site name]. Do you really want to log out?” confirmation interstitial.

And on the third (hosted on Ubuntu 24.04 with PHP 8.3), it doesn’t log you out at all. Instead, it takes you right back to the admin dashboard. It’s like it never even hits the wp-login.php file. (I recently upgraded the server and PHP for this instance, but the behavior on Ubuntu 22.04/PHP 8.1 was exactly the same.)

Whether the plugin is Network Active or activated per-subsite doesn’t seem to make any difference. And when I have the plugin activated per-subsite on the third instance, those subsites without the plugin being active log out just fine.

Thanks.