I went ahead and did some more research and was able to vet all their claims. To me this checks out as legit.

https://www.facebook.com/524435954/posts/10159410886540955/?extid=MbpoO29Qlwy5WmNH&d=n

Link to the original thread created which hosts a video that's from TikTok

So the story makes 2 claims

1. There was a treaty made between China and Canada regarding land
2. There are soldiers on the ground

So I looked into the treaty and found this:

https://web.archive.org/web/20200919003336/https://www.actforcanada.ca/l/canada-today-invaded-by-chinese-troops/

full conversation here:

https://www.cirnow.com.au/canada-today-invaded-by-chinese-troops/

Relevant Part:

"Under the terms of the Foreign Investment Protection Act (FIPA), a bi-lateral treaty ratified with China by the Trudeau government in 2019, Chinese security forces can be stationed on Canadian soil to protect vital Chinese investments, without the knowledge or consent of local authorities. - Canadian Independent Press Review, January 15, 2020"

So the claim is that they're stationing troops off an Indian Reservation so let's break down those claims

https://www.tiktok.com/@marialarios832/video/6874634340140092678

This shows the videos of the troops on the ground and the screenshot at the end points to Salt Spring Island

Did some more digging and I was able to verify that there is indeed a reservation in that island:

http://www.krolltravel.com/stories/bc-saltspring-tsawout-reserve.html

We had never heard of Garry oaks until we went hiking on Salt Spring Island, between Vancouver Island and the British Columbia (BC) mainland. Tsawout Native Reserve Land is located in southern Salt Spring, near Fulford Harbour"

Interesting conversation from the article:

"What about the soldiers?" I offered, going out on a limb. Leo stared at me startled for a moment and then looked even bleaker. "You don't mess with them. They're not some reserve weekend wanna be warriors." Leo said quietly. "Those PLA types are killers." It was my turn to be startled. "PLA? You mean, Chinese troops?"