Why did this happen?
The most likely scenario is that your updates are out of sync.
This could easily happen if you updated one and neglected to update the other or chose to download updates during installation on one and not the other.
Another possibility is you may be using different mirrors to update the machines. Some mirrors are farther behind than others. this also could easily lead to your kernel versions being out of sync.
You might also have manually installed a newer kernel on one machine and not the other.
What can I do?
How to bring them into sync should be obvious once you've determined the root cause of your issue.
1 and 2: update and upgrade both systems on the same schedule using the same mirror.
3: If you are going to manually install a kernel, repeat the process on both systems.
Note: If you require both systems to be running a specific kernel you may want to hold a particular package to prevent it being updated. Be aware of any concerns regarding security if you take this approach.
uname -a
from both the host and the guest – hellozee Sep 11 '18 at 18:15