grub failed to install on sda at last step of fresh install

Happens for both Mint and Ubuntu on new Dell Laptop. 256SSD+1T and installer only sees 1T (which is D: not C: in Win10). Just trying to get it to dual boot, can't get Linux to install.

ProblemType: Bug
DistroRelease: Ubuntu 19.10
Package: ubiquity 19.10.21
ProcVersionSignature: Ubuntu 5.3.0-18.19-generic 5.3.1
Uname: Linux 5.3.0-18-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu8
Architecture: amd64
CasperVersion: 1.427
Date: Thu Jan 16 19:55:49 2020
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed only-ubiquity quiet splash ---
LiveMediaBuild: Ubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017)
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)