Docker Compose部署AWS ECS遇镜像拉取权限不足错误求助

• 本地默认上下文执行docker compose up可正常启动容器，按照AWS官方指南尝试将镜像部署到ECS，切换到ECS相关上下文（三种选项均试过）后执行docker compose up，出现以下错误：

INFO trying next host error="pull access denied, repository does not exist or may require authorization: server message: insufficient_scope: authorization failed" host=registry-1.docker.io
pull access denied, repository does not exist or may require authorization: server message: insufficient_scope: authorization failed

• 已配置IAM用户并添加了所需权限，镜像同时存储在AWS ECR和Docker Hub，两者均尝试过部署，但问题未解决。

附Dockerfile内容：

FROM php:7.4-fpm

# Arguments defined in docker-compose.yml
ARG user
ARG uid

# Install system dependencies
RUN apt-get update && apt-get install -y \
git \
curl \
libpng-dev \
libonig-dev \
libxml2-dev \
zip \
unzip

# Clear cache
RUN apt-get clean && rm -rf /var/lib/apt/lists/*
RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer

# Install PHP extensions
RUN docker-php-ext-install pdo_mysql mbstring exif pcntl bcmath gd

# Get latest Composer
COPY --from=composer:latest /usr/bin/composer /usr/bin/composer

# Create system user to run Composer and Artisan Commands
# RUN useradd -G www-data,root -u $uid -d /home/$user $user
RUN mkdir -p /home/$user/.composer && \
chown -R $user:$user /home/$user

# Set working directory
WORKDIR /var/www

USER $user

内容的提问来源于stack exchange，提问作者Frankinstyyn