Error reloading project with IJ and Gradle 6.5

When I try to reload my project with Gradle in IntelliJ I get a failure.

FAILURE: Build failed with an exception.

* Where:
Initialization script 'C:\Users\yateu\AppData\Local\Temp\ijinit.gradle' line: 4

* What went wrong:
Could not compile initialization script 'C:\Users\yateu\AppData\Local\Temp\ijinit.gradle'.
> startup failed:
  initialization script 'C:\Users\yateu\AppData\Local\Temp\ijinit.gradle': 4: unable to resolve class org.jetbrains.plugins.gradle.tooling.internal.ExtraModelBuilder
   @ line 4, column 1.
     import org.jetbrains.plugins.gradle.tooling.internal.ExtraModelBuilder
     ^
  
  1 error


* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 57ms

This happens with IJ 2020.2EAP (202.5958.24), Gradle 6.5(.1), OpenJDK 14.

• Switching to IJ 2020.1.2 leads to the same problem.
• Switching to Gradle 6.4.1 works fine.
• I also tried to use a very basic build.gradle by just applying the java plugin but got the same error.

The first few lines of the ijinit.gradle is the following (and we can see the import that fails):

import org.gradle.api.internal.project.ProjectInternal
import org.gradle.tooling.provider.model.ToolingModelBuilderRegistry
import org.gradle.util.GradleVersion
import org.jetbrains.plugins.gradle.tooling.internal.ExtraModelBuilder

import java.util.concurrent.CopyOnWriteArrayList

initscript {
  dependencies {
    classpath files(["F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24.plugins/Kotlin/lib/kotlin-gradle-tooling.jar","F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24/lib/util.jar","F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24/plugins/Grails/lib/grails-gradle-tooling.jar","F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24.plugins/Minecraft Development/lib/MinecraftDev-2020.2-1.4.1-gradle-tooling-extension.jar","F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24/plugins/Grails/lib/grails-rt.jar","F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24/plugins/gradle/lib/gradle-tooling-extension-impl.jar","F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24/lib/gson-2.8.6.jar","F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24.plugins/Kotlin/lib/kapt3-idea.jar","F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24.plugins/Kotlin/lib/kotlin-plugin.jar","F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24.plugins/Kotlin/lib/noarg-ide-plugin.jar","F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24/lib/ion-java-1.5.2-2.jar","F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24.plugins/Kotlin/lib/allopen-ide-plugin.jar","F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24/lib/external-system-rt.jar","F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24.plugins/Kotlin/lib/sam-with-receiver-ide-plugin.jar","F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24/plugins/gradle-ext/lib/gradle-ext-profiler-tooling.jar","F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24/lib/kotlin-stdlib-1.3.70.jar","F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24/lib/trove4j.jar","F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24/plugins/gradle/lib/gradle-tooling-extension-api.jar","F:/Programmes/Jetbrains/apps/IDEA-U/ch-0/202.5958.24/plugins/gradle/lib/gradle-api-impldep-6.5.jar"])
  }
}

apply plugin: JetGradlePlugin
[...]

Is it a problem with my current IJ installation or Gradle 6.5 is simply not supported?

Thank you for your help.

EDIT The actual build.gradle that I'm using:

plugins {
    id 'com.github.johnrengelman.shadow' version '6.0.0'
    id "com.github.ben-manes.versions" version '0.28.0'
    id 'com.novoda.build-properties' version '0.4.1'
    id 'idea'
    id 'java'
    id 'application'
    id "io.freefair.lombok" version '5.1.0'
}

def secretsFile = new File(".", "secrets.properties")

if (!secretsFile.getParentFile().exists()) {
    secretsFile.mkdirs()
}

if (!secretsFile.exists()) {
    secretsFile.withWriterAppend { w ->
        w << "\n"
    }
}

buildProperties {
    secrets {
        using(file('secrets.properties')).or(System.getenv()).or([
                "GITHUB_USER" : "RakSrinaNa",
                "GITHUB_TOKEN": "N/A"
        ])
    }
}

group = 'fr.raksrinana'
description = 'RSNDiscord'
sourceCompatibility = targetCompatibility = JavaVersion.VERSION_14

mainClassName = project.mainClass

dependencies {
    implementation("net.dv8tion:JDA:${project.JDA_version}") {
        exclude module: 'opus-java'
    }
    implementation("com.sedmelluq:lavaplayer:${project.lavaplayer_version}")
    implementation("com.github.natanbc:lavaplayer-arm-natives:${project.lavaplayer_arm_version}")

    implementation("org.slf4j:slf4j-api:${project.slf4j_version}")
    implementation("ch.qos.logback:logback-classic:${project.logback_version}") {
        exclude group: 'edu.washington.cs.types.checker', module: 'checker-framework'
    }
    implementation("fr.raksrinana:utils.http:${project.raksrinana_utils_version}")

    implementation("com.beust:jcommander:${project.jcommander_version}")
    implementation("com.fasterxml.jackson.core:jackson-core:${project.jackson_version}")
    implementation("com.fasterxml.jackson.core:jackson-annotations:${project.jackson_version}")
    implementation("com.fasterxml.jackson.core:jackson-databind:${project.jackson_version}")
    implementation("org.apache.httpcomponents:httpclient:${project.httpclient_version}")
    implementation("org.apache.commons:commons-lang3:${project.lang3_version}")
    implementation("org.reflections:reflections:${project.reflections_version}")
    implementation("com.vdurmont:emoji-java:${project.emoji_java_version}")
    implementation("org.imgscalr:imgscalr-lib:${project.imgscalr_version}")
}

repositories {
    maven {
        url = 'https://repo.maven.apache.org/maven2'
    }
    maven {
        url = 'https://jcenter.bintray.com'
    }
    maven {
        url = 'https://maven.pkg.github.com/RakSrinaNa/JavaUtils/'
        credentials {
            username buildProperties.secrets['GITHUB_USER'].string
            password buildProperties.secrets['GITHUB_TOKEN'].string
        }
    }
}

import org.apache.tools.ant.filters.ReplaceTokens

processResources {
    doFirst {
        from 'src/main/resources'
        filter(ReplaceTokens, tokens: [project_version: project.version, project_name: project.name])
    }
}

compileJava {
    inputs.property("moduleName", moduleName)
    doFirst {
        options.compilerArgs = [
                '--module-path', classpath.asPath,
        ]
        classpath = files()
    }
}

test {
    useJUnitPlatform()
}

application {
    mainModule = project.moduleName
    mainClass = project.mainClass
}

java {
    modularity.inferModulePath.set(true)
}

shadowJar {
    archivesBaseName = project.name
    classifier = 'shaded'
    archiveVersion = ''
}

tasks.withType(JavaCompile) {
    options.encoding = 'UTF-8'
    options.deprecation = true
}

tasks.withType(Wrapper) {
    gradleVersion = project.wrapper_version
}

Though even trying with the one below gives the same error:

plugins {
    id 'java'
}

tasks.withType(Wrapper) {
    gradleVersion = project.wrapper_version
}

EDIT2: Opened an issue on JB side https://youtrack.jetbrains.com/issue/IDEA-245303