I missed something originally... VIP has permission, but default group does not (abandonedbases.vip, abandonedbases.veteran or abandonedbases.basic) so the bases will not convert until default is granted a permission too. this is why it says 0 seconds in your first screenshot. sorry for missing that, but reading the wall of text from the image is very difficult.
if you grant default a permission then players will be able to attack the base to convert it with the abandonedbases.attack permission, but the plugin will not automatically convert anything because thats disabled
"Run Once On Server Startup": false,
"Run Every X Seconds": 0.0,
I included debug steps in my edited post, but that's not necessary now. just granting permission to default group will solve the issue.