I second @unman’s suggestion, which one of the first changes you can try. In my “Pane is dead” case, I found that simply attempting to reinstall Qubes OS was sufficient, though I was installing to a USB drive (no dual-boot) and my hardware is different and older than yours.
If your problem still persists after trying the suggestions above, you can try to boot Qubes OS anyway to see what errors arise, which can at least tell you where Pane is dying. How I did this was by booting Qubes OS and pressing ESC when met with the boot screen after loading Xen, so that I can see what is actually happening. I am not familiar with dual-booting scenarios and have no idea what risks may be involved with attempting to dual-boot a known broken installation, so proceed with caution and probably a backup if you can manage it.
Also, if you can provide any logs or additional information on the errors you are seeing in Anaconda after installation fails, this may help with troubleshooting the problem as well. This is only important if the problem persists despite the possible solutions above however, so I would try them first.
Good luck,
John