Limit login disappeared from plugins folder

Hi, I have limit login attempts plugin active on a site for the last year, however, just noticed that it is completely disappeared from the plugins list page in wordpress. I even looked into the file manager via ftp and it is not visible at all in the plugins folder. I can’t even delete the plugin, it’s active in wordpress dashboard but nowhere else is is visible, how can this be? I want to delete the plugin but I can’t, not listed in the plugins page nor is it in the plugins folder in ftp file manager. This is so strange and I really need help trying to delete this plugin, please help!!!