Nope, Canva's pretty safe for stock stuff: https://www.canva.com/learn/content-licensing-agreement-explained-stock-images-copyright/

Full licence info here:

https://www.canva.com/policies/content-license-agreement/

It pretty much says 'yeah cool go for it as long as you've made changes to the original materials.' Which, as far as I'm concerned (not a lawyer! Lol,) means that it's good-faith on the user's part. If Canva has breached the terms with their designers, that's on them. You've 'bought' (even for free,) in good faith, on the understanding that you can use these things for these purposes.

That's not to say some people won't try it on - a lot of those horror stories are people who have not had a breach of their copyright claiming that they have. And then everyone gets scared cos even if they're in the right, they don't wanna get sued, so they avoid the product and go to places like AI which are, ironically, less of a sure-bet on the licencing front.

(I know this because I am aware that with my bad luck, I will be the one that gets sued if my metaphorical ducks aren't in a row! But on the plus side, my A-level in Law means that I'm not afraid of legal terms and have the confidence to back myself up so long as I've checked the things!)