The Find And Replace dialog/popup is hidden under the full screen overlay. I've experienced this while using the Gin and Claro themes.
The same thing issue occurs if you are start with the default state of CKEditor, click find and replace then click full screen. The find and replace dialog will no longer be visible.
I'm not sure if this is the best fix but I added the following CSS selector (highlighted in bold) to fullscreen.css. I added this below the existing .ck-fullscreen-overlay .ui-dialog selector
.ck-fullscreen-overlay .ck-dialog-overlay {
z-index: calc(var(--ck-z-modal) + 2) !important;
}
Active
1.2
Code
Thank you @todea for reporting and fix.
I tested the fix and it will be added in next relase planned for tomorrow.
Since the code for full screen is within the CKEditor 5 Premium Features module (it was created before we have released Plugin Pack) the fix was released in it's 1.3.3 version (it is a dependency for Plugin Pack).