我无法在 Ubuntu 20.04 操作系统上更新内核。执行以下命令后：
sudo apt-get update
sudo apt-get upgrade
我收到以下命令响应：
me@ubuntu:~$ sudo uname -sr
Linux 5.4.0-81-lowlatency
me@ubuntu:~$ sudo apt-get dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
我如何才能找出阻碍内核更新的原因？