Canadian Hazmat but originally American freight

First you need Hazmat Endorsement for Hazmat. Woe onto you for not having that here.

I am led to believe it is hazmat. UN 3099 and Class 9 for a minimum of 1000 pounds in the USA.

IF your bills at shipper says HM Column checked yes then YOU need diamonds on it in the USA.

https://nj.gov/health/eoh/rtkweb/documents/fs/0931.pdf

Hazmat Class 9 - Google Search:

 

I'd actually ask the Canada guys on this one. @not4hire may have some intel. Sorry I don't have more for you; when I ran into Canada it was non HZ vans. Best of luck!

 

I get class 8, un3264 pg class III - corrosive liquid, acetic, inorganic NOS

 

Ok Thats understandable.

What I am trying to illustrate that any hazmat moved in the USA from shipper has to have diamonds and driver needs hazmat endorsement either from Canada (Home country) or USA etc.

That is as far as I dare to go out on this limb.

 

It has been decades since I did transportation of dangerous goods (TDG) and the regulations were just updated (as in, this month). So, rather than speculate, here are some links:

Transportation of Dangerous Goods (TDG) - Overview

Transporting Dangerous Goods - Province of British Columbia​

 

In Canada the trucking company you haul for issues their own Transportation of Dangerous Goods card to authorize you to haul Dangerous Goods for them and show that you have had training for it.
Both countries have agreements to accept each other's qualifications. Your HazMat endorsement qualifies as a TDG card. A FAST card qualifies a Canadian the same as a HazMat background check.
So technically your company is right, you do not need a HazMat endorsement to run in Canada, but then the company is required to give you a Transportation of Dangerous Goods Card . Without one, you will be put out of service.
They could set you up with one from a website such as:
TDG by Ground | Online Certification Program - $29.95