That doesn't seem right. As a next step, we'd recommend sending a feedback report directly from your YouTube account with these steps: https://yt.be/help/RYwc . While you may not get a direct response, we do review and use the details to investigate and fix issues.
what I've heard in the past is they will randomly performan cleanups of what YT suspects are bots accounts or something and 'readjust' values after the fact.
How do you lose views?