Installation fails

[alois at astro.ch]

I downloaded install-tl-unx.tar.gz, unpacked it and ran the install script in 
install-tl-20210810
After running busily more than an hour, an RHEL 7, it failed with this output:

Retrying to install: projlib [689k]
TeXLive::TLUtils::check_file_and_remove: checksums differ for /tmp/3kSrMiXNwl/Fcm9Z2yOQa/projlib.tar.xz:
TeXLive::TLUtils::check_file_and_remove:   tlchecksum=ddccd3863f67ffa2dc195c3af705b4b520078d5ab64027bc1e66ac88a35e6622b6f4b71d03978ebe6fe1659221aadfcdbf4dab18361e55704fadc871256cfe2f, arg=15122837f9934ccc25faf35862217be9194f544c49a9a46c194154d8412ca6b90496efe25b563b7d597fa42785c55fe1836128935e8af38a5539b3f896d5ceaa
TeXLive::TLUtils::check_file_and_remove: backtrace:
-> tlpkg/TeXLive/TLUtils.pm:2399: TeXLive::TLUtils::check_file_and_remove
-> tlpkg/TeXLive/TLPDB.pm:1978: TeXLive::TLUtils::unpack
-> tlpkg/TeXLive/TLPDB.pm:1813: TeXLive::TLPDB::_install_data
-> tlpkg/TeXLive/TLPDB.pm:1729: TeXLive::TLPDB::not_virtual_install_package
-> tlpkg/TeXLive/TLUtils.pm:1633: TeXLive::TLPDB::install_package
-> ./install-tl:2135: TeXLive::TLUtils::install_packages
-> ./install-tl:946: main::do_install_packages
-> ./install-tl:700: main::do_installation
TeXLive::TLUtils::check_file_and_remove:   removing /tmp/3kSrMiXNwl/Fcm9Z2yOQa/projlib.tar.xz, but saving copy in /tmp/7Y5wW8dS6z
TLPDB::_install_data: downloading did not succeed (check_file_and_remove failed) for https://ftp.snt.utwente.nl/pub/software/tex/systems/texlive/tlnet/archive/projlib.tar.xz
Installation failed.
Rerunning the installer will try to restart the installation.
Or you can restart by running the installer with:
install-tl --profile installation.profile [YOUR-EXTRA-ARGS]
./install-tl: Writing log in current directory: /home/contrib/install-tl-20210810/install-tl.log

What am I supposed to do?