In reply to Have_A_Doubt:
What you are doing is OK. You can also use the endpoint of a sequence.
For example,
// BAD: DO NOT USE .triggered, use the @(sequence_name)
// But a better approach is to have support logic generate the sampling trigger event
covergroup frame @(Detect_EOP.triggered ) ; ...
sequence Detect_EOP; ...
After further thoughts, it was a mistake to allow the trigger of the covergroup to also be @(seqquence_name).
The regions at which variables are updated affect the outcome.
One should not think of "regions"when writing code.