Determine the cause of these warnings

Log entries

    2019-03-27 18:42:09.812  WARN 400 --- [io-8080-exec-10] o.s.web.servlet.PageNotFound             : No mapping for POST /inform
    2019-03-27 18:42:24.923  WARN 400 --- [nio-8080-exec-1] o.s.web.servlet.PageNotFound             : No mapping for POST /inform
    2019-03-27 18:42:39.961  WARN 400 --- [nio-8080-exec-2] o.s.web.servlet.PageNotFound             : No mapping for POST /inform
    2019-03-27 18:42:54.998  WARN 400 --- [nio-8080-exec-3] o.s.web.servlet.PageNotFound             : No mapping for POST /inform

I cannot find the source of this issue, I have googled for /inform endpoints and the full line even can't find anything related to this

Because its a warning it is not effecting the outcome that I can see but I would like to controll this by the time I go into production

My suspicion was that its generated by spring-boot but there is no documentation about it's existance.

Does anyone know what causes this? It might just work for me if I can controll it!

My dependencies is:

    <dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>org.jsondoc</groupId>
        <artifactId>spring-boot-starter-jsondoc</artifactId>
        <version>1.2.20</version>
    </dependency>
    <dependency>
        <groupId>org.jsondoc</groupId>
        <artifactId>jsondoc-ui-webjar</artifactId>
        <version>1.2.20</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.module</groupId>
        <artifactId>jackson-module-kotlin</artifactId>
    </dependency>
    <dependency>
        <groupId>org.jetbrains.kotlin</groupId>
        <artifactId>kotlin-reflect</artifactId>
    </dependency>
    <dependency>
        <groupId>org.jetbrains.kotlin</groupId>
        <artifactId>kotlin-stdlib-jdk8</artifactId>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-tomcat</artifactId>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    </dependencies>