Installing from 128GB USB stick, created and verified with BalenaEtcher 2.1.0.
Installing to a 500 GB Samsung SSD 980 m2 SATA drive. (Complete disk to be used)
Problem:
After navigating through the installation wizard up to the point when the "Install now" button is supposed to be clicked, nothing appears to be happening anymore, there is no visual feedback about anything going on. I left the system running overnight, the installation did not finish. The "Install now" button is greyed out (after clicking it), the "Back" button is still usable, the focus shifts from UI item to UI item when hitting tab, so the system is not "dead".
I have seen here some having issues using big USB sticks. I know you are trying to install Pro, but could you try a smaller USB. Also try a different USB creation tool, (e.g. Rufus) as Balena has a mixed reputation.
Are Secure Boot and Fast Boot in BIOS disabled? If Windows is installed: Is Fast Start-Up in Windows disabled?
Like @zabadabadoo, I would suggest to take a smaller USB Stick (32GB or less) and use a different Tool. If You have Windows, I could recommend Rufus. For Linux would be tools like Popsicle, or Impression.
When using Rufus, choose on the ''Partition Sheme'' Option GPT for Your UEFI BIOS.
I went through the checklist, my BIOS settings comply with what is recommended. BIOS is set to UEFI, no legacy support. I have a Windows 10 VM that I can fire up to try Rufus, unfortunately, my remaining USB sticks are too small for the Zorin Pro ISO. I'll get back to you after trying the Rufus route.
Another option, if the 128GB USB is all you have, could be Ventoy. You will be able to save a number of different bootable .iso's on the USB stick using that tool.
I am not sure if your large 128GB USB stick would give problems even with Ventoy, as I have no experience of that.
Thanks again for the support, I came up with a solution, though I'm not clear on the root cause of the problem.
It turned out that the installation medium wasn't the problem - it was the installation target drive.
I have 2 m2 drives in my PC, both 500GB, one is nvme, the other is SATA. I originally chose the SATA drive, used that in a previous installation already (Proxmox). Choosing this drive gets the installation stuck, no warning about the deletion of partitions, nothing. Choosing the nvme drive as an installation target works flawlessly. The next setup screen pops up immediately and after acknowledging the deletion of partitions, the installation starts.