Commenting disallowed. Being hacked? A bug?

Now using 3.3.1. Was using 3.2.1 until today.

Commenting settings in my blog https://john-s-allen.com/blog have been repeatedly reset to disallow commenting, without any input from me. This included not only changing the individual settings on a large number of posts but also changing global settings to require a login, when I only was requiring approval of the first comment.

Is this a known bug? Something that went awry in my database? Or is my blog being hacked? And to what end?

I am also getting quite a number of registrations to my blog from e-mail addresses that aren’t associated with anyone I know or who I think have any interest in its content. This suggests hacking.

I changed the admin password to the blog and it still happened. Now I have changed the password to access mysql at my internet provider. Will see what happens. Suggestions?

I do know how to reset the settings globaqlly using sql but I shouln’t have to do this!