We are aware of an issue affecting new users of Pitch n Time LE, in Logic Pro X 10.4.5 or higher, which results in Logic's plug-in manager not detecting Pitch n Time LE.
If you already have Pitch 'n Time LE installed, and validated, in a previous version of Logic Pro X - while it will not show in the plug-in manager - it can still be used as an algorithm in Logic's Time and Pitch machine.
If you've not validated Pitch 'n Time LE in Logic Pro X, prior to version 10.4.5, then the plug-in will not show in Logic's plug-in manager, and thus you will not be able to validate it. This also means you will not be able to select it as an algorithm in Logic's Time and Pitch machine.
We are currently investigating the issue and hope to provide an update at a later date.
If you are affected by this issue, please get in touch via: https://serato.com/contact.
NOTE: This issue does not affect use of Pitch 'n Time LE in compatible versions of Pro Tools.