This is was a funny thread. Initiated and solved by the same person.

For anyone who faces this issue, i found that the cause of the problem was that in Paper space i had the annotation visibility in the bottom right corner turned off. When i alternated between scales say 1:4 / 1:20 etc. with the Annotation Visibility for all scaled turned off the annotations and blocks dissipated.

In paper space double click you view port to activate it, then turn on the Annotation Visibility and it should solve the invisible annotations and blocks.