I have it running but I couldn't tell you how I got there. I remember it being a pain to install and Sophos had convoluted instructions. I think after I installed it didn't seem to be working but after a reboot it was indeed working.
I had the exact same problem. I suspect it was either APFS or full disk encryption. I thought I had found some command line way to resize the partition but it did not work. I have multiple backups so I just decided to delete and start fresh.
Deepin works great after install and I had the least...