How to disable automatic history-populated shortcuts and show ONLY manually pinned sites?

Hello, ​I am trying to customize the "Shortcuts" section on both Firefox for Android and Desktop homepage. I only want this section to display websites that I have explicitly pinned or added myself. ​However, if there are any empty slots left in the shortcut grid, Firefox automatically populates them with random websites from my browsing history. ​Is there a hidden setting (perhaps in about:config) or a native way to completely disable these auto-generated history shortcuts, so that only my manually added sites are shown? ​Thank you