My name is Jonathan Deives. I'm an Independent Advisor and I'll be glad to help you today.
Notepad itself does not have a cache, it is probably related to the recent files list by Windows, follow these steps and see if the problem persists.
Open Notepad.
Right-click on the Notepad icon in the taskbar.
Right-click on the file you want to remove from the list.
Select "Remove from list".
If the file is still appearing, try clearing recent files from File Explorer;
*Open File Explorer.
*In the left sidebar, right-click on "Quick access."
*Select "Options."
*Under the "General" tab, find the "Privacy" section.
*Click the "Clear" button next to "Clear File Explorer history."