Switching from Tectonic 2.3.5 forge mod version on 1.20.1 to Tectonic 2.4.1 forge mod causes Continents to be ignored. The issue existed on newly created worlds with no other mods, only Tectonic 2.4.1 mod version and Continents mod version.

I have also faced this problem. This is a very sad problem, continents complement realistic generation very well.

Also ran into the problem on the most recent 1.21.4 fabric versions of both mods. would really love for these to be compatible, if possible!

I know, I found an awesome seed that i want to use but cant because of this. Its 1565939857 with tectonic, terralith and hopefully continents once it works.
https://map.jacobsjo.eu/?datapacks=modrinth:terralith,modrinth:tectonic,modrinth:continents&seed=1565939857 is a good map of the seed but sadly it dont look this way in game because of incompatibility

The issue doesn't seem to exist with the datapack version of Tectonic. Using the mod versions of Continents and Terralith plus the datapack version of Tectonic works great. I don't know if there is any downside to doing it this way but I have not had any issues.

The only downside with datapack is the management of it. Mods are much easier to handle.

I'm using PrismLauncher and the mod management is super easy and fluid, but datapacks seem to require more nuanced care, as it's a World thing not a Game thing.