We've shot our own feet
I would guess that the contracts & agreements that bind the Galileo project were set up with the European Court of Justice as the final arbiter in case of dispute.
Since cutting the UK's ties with the ECJ & rejecting its rulings was/is fundamental to the Brexit process, it is difficult to see how the UK can stay in the consortium. Any request by UK to stay implies a ridiculous contradiction, "We want to stay in your Club but reject its rules!"
It isn't that the EU is being difficult - we've done this to ourselves,