Last play through I had raiders and super mutants that would attack the castle , I've beaten the main quest line and am stuck doing quest for settlements but the castle hadn't come under attack is there something I have to do to initiate them to attack the castle?

Try leaving a few Salisbury Steaks outside by where they spawn as bait

Seriously ?

Basically if your defence is higher than your resources, you will be hardly attacked .


Is this a glitch , who knows , so many glitchies u wouldn't know, what is a glitch

So build more food and then wait lol

Fill your workbench with a ton of food & water (not the prewar or cooked food, but the one you can produce by farming), and by a ton, I mean A TON.

Worth a try