OK, I think you're getting confused about what devolution is and means.
Education has been devolved to Holyrood. While Westminster has decided that it will charge students fees, Holyrood has decided not to. Now, Holyrood is not a state parliament, but a devolved body. Its powers do not end at an international border, but at an internal UK border. This means that British passport holders have different bodies governing education policy, depending on where they live. I agree that it is unfair that people governed by Westminster education policy have to pay tuition fees. I think education should be free at point of use. However, Westminster disagrees.
Holyrood - with powers over education for those living in Scotland - has a policy that Scottish universities should not charge tuition fees to those for whom it has responsibility: people domiciled in Scotland. That is devolution - different policies for different parts of the UK. I - for example - do not pay prescription charges in Scotland. Although I think there is an argument that a small charge would deter people from collecting medicines they don't really need, I find it very helpful, as I have more than one repeat prescription. Were I to try to "cash" in my prescription in England, I'd have to go through a temporary patient registration procedure, and pay for my prescription. This is not anti-Scots discrimination, but a result of devolution. It is because the Health budget for England is for those domiciled in England. yes this answers the question .
Holyrood has a budget allocated by central government (Westminster) from which it pays for education for those domiciled within its writ. That budget is not for people governed by Westminster education policy (including people born in Scotland but domiciled in England).
Now, EU states are not allowed to give preferential treatment to its own students. So EU students going to Scottish universities have to have their tuition fees paid, too. However, Scotland is not the member state, the UK is. And in the rest of the UK, tuition fees are charged. This is an anomaly caused by devolution. But it is unfair to try to blame Holyrood for Westminster education policy.
If we have devolution, it is going to mean different things happening in different parts of the UK. There are two ways of trying to square the circle: independence for Scotland (which would mean English and Welsh domiciled students get paid tuition fees, too, if Scotland becomes an EU member); or a federal UK (which answers the West Lothian Question, but would not address the tuition fees anomaly).