Specifically when I debug I see that the java type shows up as

javaType!

indicating it could be nullable or non nullable, where as the kotlin type shows up as `kotlinType?`indicating nullable

For Java types with unknown nullability,

isMarkedNullable

returns

false

as documented. Checking if a type has unknown nullability is not supported at the moment (https://youtrack.jetbrains.com/issue/KT-14276)