Did you get any document to officialize your change of job title and the change of company name? E.g., even if the company is the same, did you get a different offer letter or even just a document to notify the change of job title?
I don't know if there is an official answer to this, but if this happened to me, I would still submit this information to IRCC, even if it may not be strictly necessary. If you didn't get any official document, I would just ask one to the HR that mentions your new job title.
Also, if you are applying from inside Canada and working in Canada on a work permit tied to your company and to your role, you or your company may have to notify IRCC about this in the work permit as well. This doesn't apply to you if you are applying from abroad and you don't work in Canada, but I wanted to mention just in case.