the thing is in my case, so far GCkey seems lag behind, compared to ECAS. Ecas shows DM but GCKey shows still reviewing my eligibility.
I know which part you are talking about. They do not change the "
checklist" on GCKey and that's the standard for most people. Mine is the same and all of those checklist items including "eligibility review" remain the same although they have already made decisions on SA and processing my parents' PR. But, they send several correspondences using GCKey and all of those are listed there.
The following is the message I found on my ECAS after they sent IME and PCC request. ECAS will only states when they sent the PCC and IME requests. The most important information especially for IME is the form CIC sent you. ECAS does not have that form, your GCKey does as that's where they will send the files to. I would not worry about status updates on ECAS, as the main status is the email you get from CIC with decision in it. Whether ECAS displays that decision or not, that decision you get in the mail/email/GCKey is final.
Typically speaking, GCKey is more important after you get sponsorship approval, as your LVO will communicate with you via GCKey/MYCIC account. Decision letter such as pre-arrival letter, which is usually sent after they've made decision on medical, will be sent to your GCKey in your case.
ECAS text from my files.....
"We sent AAAAAAA correspondence on January 25, 2019. If AAAAAAA has not yet provided the information or the requested documents, please have AAAAAAA do so as soon as possible. Please wait until AAAAAAA receives the correspondence before sending us additional information, as the correspondence will outline all information that is required."
But, GCKey checklist items "eligibility review, biometrics etc.." remains unchanged (i.e they do not update checklist items in GCKey).