[ksp2][room] [ksp] [SQLITE_ERROR] SQL error or missing database (near ")": syntax error)

[virogu]

room = "2.7.1"
kotlin = "2.1.21"
ksp = "2.1.21-2.0.1" // and "2.1.20-2.0.1"

After upgrading to KSP2, Room compilation failed with the following error:
[ksp] [SQLITE_ERROR] SQL error or missing database (near ")": syntax error).

Investigation revealed that the properties of inner classes were being completely removed during code generation.

For example:

@Serializable
class A {
    //Error while "kspDebugKotlin"
    @Serializable
    @Entity(tableName = "tab_a")
    class AA(
        @ColumnInfo(name = "colum1")
        val colum1: String,
        @ColumnInfo(name = "colum2")
        val colum2: String,
        @ColumnInfo(name = "colum3")
        val colum3: String,
    )
}

//This is ok
@Serializable
@Entity(tableName = "tab_b")
data class BB(
    @ColumnInfo(name = "colum1")
    val colum1: String,
    @ColumnInfo(name = "colum2")
    val colum2: String,
    @ColumnInfo(name = "colum3")
    val colum3: String,
)

Looking at the createSql in the schemas json file, table tab_a has no fields, while table tab_b is normal.
All properties of class AA are also missing during compilation.