In Sitecore XP 10.2.2 and 10.3.2, after installing a pre-release, unchecking previously selected values in a Checklist field type (for example, the Navigation Filter field based on the _Navigable template) does not persist after saving the item in the Content Editor, while selecting new values is saved correctly.
This behavior is registered as bug with reference number PDXP-13967, it only exists in older versions of the respective pre-releases.
To resolve this issue, refer to the following articles to download and install the latest cumulative hotfix for the corresponding Sitecore XP version:
For Sitecore XP 10.2: KB1001439
For Sitecore XP 10.3: KB1002844
After installing the latest version of the cumulative hotfix, saving an item after deselecting values in Checklist fields should work as expected.