Any Canadians ever got TN rejected because the officer thought you didn't have strong enough ties to Canada?
One of the requirements of the TN visa is that the job is nonimmigrant status and temporary in nature, so you have to prove that you will return to Canada (evidenced by showing strong ties to Canada like house, family, etc.) Anyone got rejected for TN due to this reason? Also if your contract doesn't have a end date, can the officer then reject you because it's not a temp contract?
TN offer letters MUST have a beginning and end dates. And it can’t be more than 3 years in the future.
The ties is indeed a huge requirement of the TN. You have to convince the admitting offer that you will come back. The most common way of showing ties is having an rich and long history in Canada like having studied, worked in Canada, lived in Canada for a long time.
Aka being Canadian, and not just there for the passport
There are people around here that count the number of days until they get their Canadian passport and already plan to apply for a TN. And by the way the question is phrased I guess the OP might be in such situation.
Just a note. Everybody does the same mistake. Getting your status rejected or denied are two different things. Rejected is they consider that your application was incomplete or bogus. Denied is when they consider you don’t comply with all the requirements.