Citizenship of another country does not affect your eligibility for Canadian citizenship in any way. Entering Canada on your UK passport should not be a problem. Maintaining your PR status in Canada could be if you don't meet the PR criteria, e.g. time spent outside Canada.
You're obliged to divulge the information about your UK citizenship when/if asked about any changes in the information as captured in your citizenship application, which is a usual and standard question at a citizenship interview (conducted after the citizenship test).
In addition, as you applied for Canadian citizenship in June and acquired British citizenship in August, I assume you had had a permanent resident status or the equivalent in the UK, which you were supposed to divulge in your Canadian citizenship application.
If I were a CIC officer, I'd have serious doubts that you would be able to meet the residency criteria in both countries, UK and Canada, in parallel, considering you received your UK citizenship the same year you applied for Canadian citizenship.
Your "strong ties" to Canada are close to irrelevant in terms of citizenship eligibility if you can't satisfy the officer that you meet the requirements of physical residency/presence in Canada, as alphazip said.