Failure of Single Conductor 34.5kV XLPE Cable Due to Circulating Current

We have 34.5kV single conductor 630mm2 run for approx 1.5Km from SWGR to Xformer (12 cables 4 cirts of 3 cables to 4 Xformers.

WSe have Link Boxes at Source and Xfmr end with Surge Volt Limiters and the Shield and Armoured bonded together and individualy run to the link Boxes

We additionall y haved 3 joints on the run. @ joint are the conventional Raychem type with the Shield and Armour isolated form each other.

The mid point joint has the Armour and the Shield bonded together on both the load side of the joint and the source side of the joint with the load aside and the source side isolated from each other.

These are run to Link Box and connected in WYE to Earth

Although the connections are A B C on one set (load) and C B A on other set (source). We have current in the three connections on the load side and zero on the source side.

Two cables have failed at the armour spring ring at the last joint specifically at the side coming from mid point Link Box.

The other cables have been checked and we are experiencing very high temps at the spring ring at the other final joints

We have attempeted cross bonding at the mid point and have reduced the Circulating current in two phases to a minimum but still have a very high current in one phase.

I believe in isolating the armour bond to earth at the load end as I believe this is what is causing the circulating current to be high.

Any othe solutions????