And think Android Compose is not on 1.4.20 as well

Thanks, I'll stay on 1.4.0 for now

You can use 1.4.10 as well

Yeah, TLDR is that Compose depends on some kotlin compiler internals and is thus fairly tightly coupled to Kotlin versions. You need to use the versions of Compose that are compatible with specific versions of Kotlin and vice versa. The version of Compose that supports Kotlin 1.4.20 should be coming soon, although I think the next scheduled release/opportunity is after thanksgiving.