What I am saying and have done is to select the Fat 32 partition, normally the ESP or EFI boot partition on the Windows disk (in this case), click on the right with the mouse, go to manage flags and untick the boot flag. It will untick the esp flag as well. Then, do the Solus install. Once it's done, you can reset the boot flag of the windows partition.
It will go back to boot and esp. It hasn't made any trouble on all my partition (Windows, OpenBsd, Mint, Solus and Fedora). It's just the time of the install. I found it here : https://discuss.getsol.us/d/4467-installer-not-seeing-new-efi-boot-partition

Hi,
I went into the same problem (I have around 10 disks !!). On each ESP partition (boot Fat 32 parttion), with Gparted (didn't work with Kdedisk manager (can't remember the exact name)), I unticked flag boot (it comes with esp), that changed then to msftdata with the manage flags menu.
If your disk is empty, then on install, it will ask you if you want to create an Esp partition on the disk you expect. I actually found this solution on the forum (can't find it again, but it's there).
I would say on your case, you untick the boot flag of the windows partition, and bob's your uncle. (by the way, you can install Gparted with the live iso, it works fine).

So, problem partially solved.
I first tried to change the burner device with another one, same problem occurs.
I finally change the SATA plug : instead of using the SATA plugs of my PCIe SATA 2 card adaptor, I plug the burner device directly to
one of my motherboard SATA plug. Then, everything worked fine.
So, I said partially, because it seems that using a SATA adaptor card won't allow a burner device to work correctly.
Anyway, I think the problem can be considered as resolved.

Other thing :
if I put an audio CD and launch SoundJuicer, the program doesn't start and doesn't read the CD.
But it starts with Asunder, read the CD and extract audio normally.
I guess they are not using the same method to use/contact the device and, one is working not the other.

Something I just noticed that might help.
If I start a program like SoundJuicer, without a disk in the device, it starts immediately.
If there is a writable cd in the tray and I start SoundJuicer, then nothing happens. By pressing the Eject button on the device,
it takes around 30 seconds for the cd to eject, and then SoundJuicer starts.
Hope it helps a little.

I actually tried it as normal user, and I tried it as root, with the same result.