Cannot download or update snapshot dependency hosted on Github Package Registry using gradle - gradle

Question

I have an issue with Github Package Registry when I try to push or download SNAPSHOT versions of ny gradle plugin.
When I first send publish my package everything works fine but then when I try to install or update this package, I get the following errors:
The usage of a fixed version (without snapshot) seems to work (even though the update does not work but that may be on purpose as it's a 422 error).
Here is my build.gradle.kts file if it helps.
group = "com.github.imflog"
version = "0.10.0-SNAPSHOT"
plugins {
kotlin("jvm").version("1.3.71")
id("java-gradle-plugin")
id("com.gradle.plugin-publish") version "0.11.0"
id("maven-publish")
id("com.github.ben-manes.versions") version "0.28.0"
}
repositories {
jcenter()
mavenCentral()
maven("http://packages.confluent.io/maven/")
}
java {
withSourcesJar()
}
// Dependencies versions
val confluentVersion = "5.4.1"
val avroVersion = "1.8.2"
dependencies {
implementation(gradleApi())
implementation(kotlin("stdlib"))
implementation("io.confluent", "kafka-schema-registry", confluentVersion) {
exclude("org.slf4j", "slf4j-log4j12")
}
}
// Test versions
val junitVersion = "5.6.1"
val mockkVersion = "1.9.3"
val wiremockVersion = "2.26.3"
val assertJVersion = "3.15.0"
dependencies {
testImplementation(gradleTestKit())
testImplementation("org.junit.jupiter", "junit-jupiter-api", junitVersion)
testImplementation("org.junit.jupiter", "junit-jupiter-engine", junitVersion)
testImplementation("org.assertj", "assertj-core", assertJVersion)
testImplementation("io.mockk", "mockk", mockkVersion)
testImplementation("com.github.tomakehurst", "wiremock-jre8", wiremockVersion)
}
tasks.withType<Test> {
useJUnitPlatform()
}
publishing {
repositories {
maven {
name = "GitHubPackages"
url = uri("https://maven.pkg.github.com/ImFlog/schema-registry-plugin")
credentials {
username = System.getenv("GITHUB_USERNAME")
password = System.getenv("GITHUB_TOKEN")
}
}
}
}
val registryPluginName = "com.github.imflog.kafka-schema-registry-gradle-plugin"
gradlePlugin {
plugins {
create("schema-registry") {
id = registryPluginName
description = "A plugin to download, register and test schemas from a Kafka Schema Registry"
displayName = "Kafka schema registry gradle plugin"
version = version
implementationClass = "com.github.imflog.schema.registry.SchemaRegistryPlugin"
}
}
}
pluginBundle {
website = "https://github.com/ImFlog/schema-registry-plugin"
vcsUrl = "https://github.com/ImFlog/schema-registry-plugin.git"
tags = listOf("schema", "registry", "schema-registry", "kafka")
}
Thank you !