Missing version when using bom - maven

Question

I'm trying to create a multi module Maven Spring project:
Parent
|-Bom
|-Customers
|- Customers-main
|- Customers-client
|- other modules...
The idea is all projects import the bom so I can keep version consistent across modules.
When trying to build the Customers module, I get these errors:
[ERROR] The project com.imgarena:customers:0.0.1-SNAPSHOT (C:\dev\IMGArena\customers\pom.xml) has 2 errors
[ERROR] 'dependencies.dependency.version' for io.springfox:springfox-swagger2:jar is missing. # line 52, column 21
[ERROR] 'dependencies.dependency.version' for io.springfox:springfox-swagger-ui:jar is missing. # line 56, column 21
Inside IntelliJ, the versions are resolved correctly (it even shows the gutter icon that jumps to the bom when clicked):
But when running with Maven 3.6.3 CLI, I got the error.
Parent pom.xml: (most dependencies are removed for brevity)
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.imgarena</groupId>
<artifactId>parent</artifactId>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.4.1</version>
<relativePath/>
</parent>
<!-- chaged fom jar to pom -->
<packaging>pom</packaging>
<version>0.0.1-SNAPSHOT</version>
<modules>
<module>customers</module>
</modules>
<properties>
<maven.compiler.source>15</maven.compiler.source>
<maven.compiler.target>15</maven.compiler.target>
<spring-cloud.version>2020.0.0</spring-cloud.version>
<springfox-version>3.0.0</springfox-version>
</properties>
</project>
Bom pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.imgarena</groupId>
<artifactId>bom</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>pom</packaging>
<parent>
<groupId>com.imgarena</groupId>
<artifactId>parent</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<dependencyManagement>
<dependencies>
<!--SpringFox dependencies -->
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger2</artifactId>
<version>3.0.0</version>
</dependency>
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger-ui</artifactId>
<version>3.0.0</version>
</dependency>
</dependencies>
</dependencyManagement>
</project>
customers pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<parent>
<artifactId>parent</artifactId>
<groupId>com.imgarena</groupId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>customers</artifactId>
<packaging>pom</packaging>
<modules>
<module>customers-client</module>
<module>customers-main</module>
</modules>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<dependency>
<groupId>com.imgarena</groupId>
<artifactId>bom</artifactId>
<type>pom</type>
<scope>import</scope>
<version>0.0.1-SNAPSHOT</version>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<!--SpringFox dependencies -->
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger2</artifactId>
</dependency>
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger-ui</artifactId>
</dependency>
</project>

Answer 1

Apparently the reason was I was missing including the bom as a module in the parent pom:
<modules>
<module>customers</module>
<module>bom</module>
</modules>
Don't know exactly why, but once I added this everything worked.