Are AI bot's hitting your site?
There may be a time when you see a lot of traffic coming from a specific ISP - AI bots are more prevalent now, and sometimes alternate between different IPs. This trick of alternating IPs is how they evaded inbuilt server IP filtering measures that are created to deter this kind of traffic. They sometimes pretend to know URL patterns and may prepended with the 404.html. Yes - more information than you wanted to know.

Your site is not in any danger of being hacked when this happens. AI bot traffic is no different than Google and Facebook crawling the site but the AI bots tend to be more aggressive. Your hosting company has been implementing measures against these bots and will continue to refine those measures in the future.