probably your system is trying to update by itself as well?
You can try the command
ps -efl | grep apt
ps -efl | grep dpkg
if something shows up other than the command typed is because there is another apt task running in the bacground. you have to wait until it finished or you can kill the process and then run the update again
Click Accept as Solution to acknowledge that the answer to your question has been provided.
The button appears next to the replies on topics you’ve started. The member who gave the solution and all future visitors to this topic will appreciate it!
These simple actions take just seconds of your time, but go a long way in showing appreciation for community members and the LIVEcommunity as a whole!
The LIVEcommunity thanks you for your participation!