CAUTION: The suspending of an application under section 13.1 in the Citizenship Act is almost always SERIOUS.
It warrants at the least visiting the website linked by
@wvo2017:
https://www.canada.ca/en/immigration-refugees-citizenship/corporate/publications-manuals/operational-bulletins-manuals/canadian-citizenship/admininistration/general-file-processing/procedure-suspending-applications.html
For Section 13.1 in the Citizenship Act see
http://laws-lois.justice.gc.ca/eng/acts/C-29/page-5.html#h-7
The suspending of the application almost certainly means there is an INVESTIGATION in progress. And not a mere review of the particular eligibility requirements.
Applications can be suspended for YEARS. And, indeed, it appears that suspended applications quite often do encounter very long delays, many of them for YEARS.
And NO, this is not about failing to disclose a single day-trip to the U.S. It could be about misrepresentation related to travel history disclosures, but that would not be triggered by an isolated omission even if the omission was for an absence of many days.
I suspect you may deny knowing what this is about BUT that in fact you probably do have a very good idea what it is about. Or, if you think about it, you will have a good idea. Depending on what that is,
you might want to seriously consider seeing a lawyer.
As you noted in your account of the test event, you were quite likely flagged before the test and interview.
Additional observations:
The decision to suspend an application is made by a Citizenship Officer, not just any processing agent.
There are all sorts of issues or problems which IRCC can and will make further inquiries regarding, even initiate some level of investigation, which HOWEVER will NOT trigger the suspending of the application.
For Example:
-- IRCC's discovery of a significant discrepancy in the applicant's travel history, for example, will typically lead to IRCC digging deeper and also making additional requests of the applicant, but even if the discrepancy suggests deliberate misrepresentation this does not typically result in suspending the application.
-- IRCC suspects the applicant may be prohibited for a criminal charge in Canada, for another example, and makes a referral to the RCMP.
Neither of these are likely to result in suspending the application. But they are of course serious matters.
Issues leading to the suspending of the application tend to be significantly more serious.
I cannot guess what the problem is in a particular case, but we know the more common reasons why applications are suspended:
-- pending inquiry/investigation of PR-refugee for potential cessation of protected person status (clearly NOT applicable here)
-- pending investigation of fraud (not mere misrepresentation in the Citizenship Application, so more likely for misrepresentations possibly made earlier in the immigrant's history, in the original PR application perhaps, or in a PoE examination at some time)
-- pending CSIS investigation for security concerns
-- pending RCMP investigation for criminality concerns (such as alleged involvement in a criminal organization, which could make a PR inadmissible even if NO criminal charges are made against the PR)
(In the not-so-distant past, IRCC also suspended applications pending inquiry/investigation/proceedings related to alleged breach of PR Residency Obligation. This has been less common in recent years; was more common when applications were often taking two or more years, and the applicant was living abroad in the meantime, living abroad long enough to potentially encounter PR RO compliance issues.)
Again, all these tend to be serious. All these can cause a very LONG DELAY (that said, some are likely to get resolved sooner than others, like the RCMP investigation is likely to get resolved a lot faster than a CSIS overseas investigation).
If you trust there really is nothing to worry about (no misrepresentations in your past, no reason for CSIS to determine there is a security concern, no criminality issues), it is possible the reason for suspending the application will be resolved in a relatively reasonable period of time (noting that based on your several expressions of impatience for the pace of processing for routine applicants, you probably need to entertain that much longer processing times are reasonable) and your application will be processed. There are, however, significant odds there is something to worry about . . . and that to get things resolved you may very well need the assistance of a lawyer.
Final note: Fraud investigations can be triggered just because the immigrant has used or been in any way associated with a consultant (authorized or not, disclosed or not) who has been investigated for fraud. It is not clear to what extent this is continuing, but it is fairly clear that even recently the RCMP, CBSA, and IRCC are targeting, for investigation, ALMOST ALL former clients of consultants involved in fraud. This has undoubtedly swept many innocent and unsuspecting immigrants into fraud investigations.