Am working on lightning lab of CKA, I upgraded cluster from 1.28 to 1.29, but this test was not cleared. I am not sure what went wrong, i could see kubeadm, kubelet versios on controlplane and node were upgraded successfully.
Deployment was also deloyed on node01 as required.
Most likely, you did not update the settings for APT. We have a FAQ about this to tell you how to do this: FAQ: Upgrading Clusters With Kubeadm
can not find any FAQs. Could you please explain better?
Please use the link and scroll down in the page. The info is there 
@Yash-Gadwal If you are doing the KodeKloud version of the course and not the Udemy one (they are exactly the same course, just on different platforms), then you may not be able to follow Rob’s link.
The content is also available here