Thank you for taking the time to visit the Community to report your issue, although apologize that you have not yet received a response.
We'll need a bit more information to be able to assist.
Please navigate to Help > About Quicken and let us know what release of Quicken you are using. This can help isolate if an issue is related to a particular release.
There a few ongoing issues with the memorized payee list as well as splits clearing, Can you please confirm if you are syncing to the mobile/web app? To so please navigate to Edit > Preferences > Quicken Mobile & Cloud Accounts.
If this is enabled, can you disable to sync to test if this clears up the issue?