Your likes are more public than you think, and clearing thousands of them by hand is hopeless. Here is how to wipe your entire likes history in bulk, and why the old ones seem to vanish when you try.
Anyone can open your Likes tab and scroll your taste, your old opinions, and things you liked years ago and forgot about. If you are cleaning up an account or just want a fresh start, your likes are worth clearing along with your posts and reposts.
This is the most common frustration. X does not render your whole likes history at once. It loads a chunk, and older likes only appear as you scroll and the newer ones are cleared. So a tool that just looks at what is on screen will seem to stop early. The fix is a tool that unlikes what is loaded, lets the next chunk load, and repeats in a loop until there is nothing left.
A browser extension can run that loop for you. It clicks unlike on each loaded post, waits for more to load, and keeps going, all inside your own browser session. No API keys, no password, no third party getting access to your account.