If you applied for your GCMS notes from CBSA or IRCC, each agency can seek extensions which is on a case by case basis. Under section 9 of the Access to Information Act. CBSA sends out extensions on very limited requests.
To read on extensions, see
https://www.canada.ca/en/treasury-b...rmation/access-information-manual.html#cha7_3
As regards IRCC, in its
2019-2020 report, IRCC stated that 49% of the requests were delayed, and 6% of the requests took longer than 120 days to be released.
Extensions are not based on the processing of your application, and this has been clarified:
There is clown here on the forum who will come jumping claiming that some websites get extensions and he found it via ATIP request. This was the case in 2019, and this was notified to the Office of the Information Commissioner after which in March 2020, a systematic investigation was initiated against IRCC.
https://www.oic-ci.gc.ca/en/resourc...r-initiates-systemic-investigation-department
The report of the investigation will be tabled before the parliament.
Most request with CBSA are released within 15-30 days, unless there is an extension, and for IRCC too now most applications are being released within 30-35 days.
If you feel that applying form one website is the reason for delay, you can file another request from another website.