Debian family OS Update

I want to ask a question about OS Update.
I have a mender-client which has a Debian 10.3 buster. The device has beaglebone black, and there is no problem about connection to the mender server, uploading/downloading artifacts, and deployments. But, when I try to use the .mender file (which I got when converting mender debian image) in order to do an OS update, the device is not rebooting itself, and I cannot see any OS update because I have added some folders and files to the OS before. Although the deployment says me successfull status in the finished deployments page, I cannot see it. Am I doing something wrong or do I know something wrong ?
Thanks in advance.