Very Heavy Fighter power issue

[Catspaws69]

Hi,
Every time I leave a base I get a message about an incompatible item only allowing a power output of 75%. I did have a Nephstys and tried changing a number of items to see if I could cure it to no avail. I have now purchased a Guardian in the hopes that swapping to a more mainstream faction ship would resolve this but I am still getting the message. I have also swapped out a number of items on this to all same faction items but it has not helped. All my weapons are of the weapon level for that slot or 1 below. Have tried different thrusters, countermeasures and engines but nothing seems to resolve the issue.
Any idea's or is this just normal for Very Heavy Fighter class?