This is a clone of issue CNV-31944. The following is the description of the original issue:
—
This is a clone of issue CNV-23926. The following is the description of the original issue:
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Description of problem:

I'm reporting all 3 weird warnings/behaviour in one as they seem all related.
The UI gives 3 warnings that does not make much sense, everything is working fine, they appear to be false alarms.

Open the OCP Web Console and:

1. Virtualization
2. Catalog
3. Select 8.x (or any OS actually)
4. Click 'Customize Virtual Machine'
5. Click 'Review and create virtual machine'
6. Go to the Disks tab
7. Detach all Disks
8. Add a new Disk, a CD-ROM that is bootable for installing Guest
Source: Use an existing PVC
Type: CD-ROM
[x] Use this disk as a boot source

Problem 1: at the top of the window, this is displayed:

~~~
Warning
Only one disk can be bootable at a time. The bootable flag will be removed from "" and placed on this disk.
~~~

The "" is obviously an empty string as there is no other disk. There is no need for this warning in this situation, we are setting a disk to bootable, its the first one, so its not being removed from any other disk.

But there is more, let's continue.

9. Click Save and add the CDROM
10. Add a new Disk, now the actual Disk to install the OS
Source: Blank (Creates new PVC)
Type: Disk
[ ] Use this disk as a boot source
11. Click 'Create VM'

Problem 2: this warning is displayed:

~~~
No available boot source
The VirtualMachine you are creating does not have an available boot source. We recommended that you select a boot source to create the VirtualMachine. You can select the boot source in the Disks tab.
~~~

It has a boot source, its the cdrom. See screenshot for reference.

12. Accept and create the VM anyway
13. Start the VM
14. Notice the VM boots from CD, there is nothing wrong with it.

Problem 3: now this warning shows at the top of the VirtualMachine details page

~~~
Pending Changes
The following areas have pending changes that will be applied when this VirtualMachine is restarted.
Details

Boot disk
~~~

Why pending changes? I did not change anything while the VM was running....

Version-Release number of selected component (if applicable):
4.11.20

How reproducible:
Always

Steps to Reproduce:
As above