grub boot crashes in my ssd if i'm online else not

[islam irgashev]

i cannot install ubuntu 20.04 if i'm online. It's normal if i'm offline and i dunno what i should do. ( Notice i use ssd to install )

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubiquity 20.04.15.10
ProcVersionSignature: Ubuntu 5.8.0-43.49~20.04.1-generic 5.8.18
Uname: Linux 5.8.0-43-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu27.16
Architecture: amd64
CasperMD5CheckMismatches: ./pool/main/l/linux-oem-5.6/linux-modules-5.6.0-1047-oem_5.6.0-1047.51_amd64.deb
CasperMD5CheckResult: fail
CasperVersion: 1.445.1
Date: Wed Jul 21 20:22:56 2021
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed maybe-ubiquity quiet splash ---
LiveMediaBuild: Ubuntu 20.04.2.0 LTS "Focal Fossa" - Release amd64 (20210209.1)
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)