It very well might be, but do you realize the SSL connection error you're showing gets nowhere close to any tracking protection functionality? The connection is not broken by Firefox, that ads.* host loads just fine with the same, main *.tiktok site wildcard certificate — you can check its details by running a sslscan or inspecting the same cert on the apex domain. It's "something" on your line interfering — a filtering DNS or a pihole, your security software or network appliance etc. This response is not coming from tiktok site (unless they misconfigured something badly) — if you click through that red error and go to "Connection failure »", then show what's not trusted or what is the certificate detail and what's the mismatch, you'll be able to understand who is trying to pretend to be ads.tiktok for you.