KotlinReflectionInternalError: Unresolved class: class java.math.BigDecimal$1

I got this error when I add the mapping "Float" to "java.math.BigDecimal" and has an input type with variable of this Float(will be converted to BigDecimal later).

Input type

input AccountInput {
	customerId: ID
	amount: Float
}

Error log:

WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.springframework.util.ReflectionUtils (file:/Users/tester/.gradle/caches/modules-2/files-2.1/org.springframework/spring-core/5.3.18/7ff3000f3342989cb011b6095a0e86f2e5176cef/spring-core-5.3.18.jar) to field java.math.BigDecimal.intVal
WARNING: Please consider reporting this to the maintainers of org.springframework.util.ReflectionUtils
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
2022-07-19 14:01:29.099 ERROR 39933 --- [nio-8089-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Handler dispatch failed; nested exception is kotlin.reflect.jvm.internal.KotlinReflectionInternalError: Unresolved class: class java.math.BigDecimal$1] with root cause

kotlin.reflect.jvm.internal.KotlinReflectionInternalError: Unresolved class: class java.math.BigDecimal$1
	at kotlin.reflect.jvm.internal.KClassImpl.reportUnresolvedClass(KClassImpl.kt:329)
	at kotlin.reflect.jvm.internal.KClassImpl.access$reportUnresolvedClass(KClassImpl.kt:44)
	at kotlin.reflect.jvm.internal.KClassImpl$Data$descriptor$2.invoke(KClassImpl.kt:56)
	at kotlin.reflect.jvm.internal.KClassImpl$Data$descriptor$2.invoke(KClassImpl.kt:47)
	at kotlin.reflect.jvm.internal.ReflectProperties$LazySoftVal.invoke(ReflectProperties.java:92)
	at kotlin.reflect.jvm.internal.ReflectProperties$Val.getValue(ReflectProperties.java:31)
	at kotlin.reflect.jvm.internal.KClassImpl$Data.getDescriptor(KClassImpl.kt)
	at kotlin.reflect.jvm.internal.KClassImpl.getDescriptor(KClassImpl.kt:182)
	at kotlin.reflect.jvm.internal.KClassImpl.isCompanion(KClassImpl.kt:283)
	at com.netflix.graphql.dgs.client.codegen.InputValueSerializer.serialize(InputValueSerializer.kt:78)
	at com.netflix.graphql.dgs.client.codegen.InputValueSerializer.serialize(InputValueSerializer.kt:79)
	at com.netflix.graphql.dgs.client.codegen.GraphQLQueryRequest.serialize(GraphQLQueryRequest.kt:47)

The error happens when it calls nestedValue::class.isCompanion as seen below

And the error will be gone if I remove the amount field from input type.

Would appreciate any help on this.

My build.gradle.kts

plugins {
	jacoco
	id("org.springframework.boot") version "2.5.12"
	id("org.owasp.dependencycheck") version "6.0.2"
	id("io.spring.dependency-management") version "1.0.11.RELEASE"
	kotlin("jvm") version "1.5.10"
	kotlin("plugin.spring") version "1.5.10"
	id("com.netflix.dgs.codegen") version "4.6.6"
}
dependencies {
	implementation("com.fasterxml.jackson.module:jackson-module-kotlin")
	implementation("org.jetbrains.kotlin:kotlin-reflect")
	implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")

	implementation(platform("com.netflix.graphql.dgs:graphql-dgs-platform-dependencies:3.10.2"))
	implementation("com.netflix.graphql.dgs:graphql-dgs-client")
}

tasks {
	generateJava {
		schemaPaths = mutableListOf("${projectDir}/src/main/resources/schema")
		generateClient = true
		language = "java"
		typeMapping = mutableMapOf(
			"JSON" to "org.json.simple.JSONObject",
			"Float" to "java.math.BigDecimal",
			"DateTimeOffset" to "java.time.LocalDateTime",
			"Decimal" to "java.math.BigDecimal"
		)
	}
...

Reproduce the AccountInput serialization with Float mapped to java.math.BigDecimal, then start at InputValueSerializer.kt line 78 and follow the call from GraphQLQueryRequest.kt line 47. Compare this path with the generated client setup in build.gradle.kts; done means the request serializes without KotlinReflectionInternalError while retaining the configured type mapping.