The real reason for all the issues.
A few weeks later I got a report on the problems with my bike.
1. The valve stem seal were leaking (yes the ones I had had fitted less than a year before)
2.The valve shims were hand made and not flat but were rounded
3. The piston rings needed replacing (yes, the same ones done less than a year before)
4. Head and barrel gaskets needed replacing (yes the ones replaced less than a year before)
5. The cam chain needed replace as well as the tensioner
6. All the carb diaphragms were split
7. The carb floats were cracked
As you can imagine I was not a happy chap, but also I was relieved to have finally got to the cause of the issues. I ordered the parts and once they arrived they were fitted.