Hey Guys, sorry about the long time away from reply... been a crazy couple of days.
Got a couple more photos of the leaves that have these blothches. they start of as tiny yellow spots, eventually get bigger and then dry, crack and eventually look like a clean hole.
The reason i started thinking yellow leaf is the black spots (spores?) can see on some of these dead zones on the leaves. That said it does also look kinda burnt/necrotic tissue.
As usual, photos should be higher rez so if you click on the actual pic name they should open up in there own tab with a heafty zoom so you can get a close looker at the damaged areas.
The 3-4 of these yellow/limp leave (not pictured) look to have come away from the dead centre of the bush, could it be a light penetration thing? They came away with some gentle pressure. Apply that same pressure to any other leave would do nothing.
There are no green/green coloured leaves falling off. These ones you see in the pictures are ones I've removed in case its yellow leaf as I'm now on potential control of spread since its won't be going away.
New fan isn't in yet, had to go out today to pick up a power cable which I just learnt yesterday after taking receipt of delivery that the RVK fan doesn't come with.