@pablom63973339,
You are absolutely correct.
Whenever you install the AEM archetype project or the WKND starter project using your maven skills, for example, mvn clean install -PautoInstallSinglePackage, at the most basic level, you are uploading and installing AEM components and scripts to AEM (you can find it in CRX/DE,http://localhost:4502/crx/de/index.jsp. At the same time, the backend bundle is being installed (typically the bundle is named "core" by using the AEM archetype project, and the .jar lives inside of the /apps/my-site/install folder which is detected by the JCR installer provider, which installs this package into the OSGI framework.).
When the backend bundle is installed, some AEM backend services are orchestrated to restart (based on the OSGI service registry rules), so that your bundle can be registered and consumed by other backend bundles.
During the services restart, some areas of your website will be affected, and this is expected. you must wait until the service is restarted for you to continue.
In summary, you must wait until the service is restarted for you to continue.
I hope this helps.
Regards,
Brian.