I have a green  portal on the island but not on the control panel ...I have included screen shots below. one showing the portal with the pet on it and one showing the portal more clearly without the pet  hopefully enough  to help you.

Next Screenshot

Oh, didn't see the second screenshot. Whoops.

Hello,

Do you have any Portal Energy Cells? Usually it doesn't activate when you have no cells left.

Thank you Angel, I completely forgot to check the portal cells :( I had a fair number on hand and had been collecting a good few as I explored, so it didn't  occur to me that I had run out.

I have started the crafting of them as  I am sure you are right....but will let you if it doesnt work.

Many Thanks :)