Install fails due to errors in temp directory

[Uwe Siart]

Even a third attempt to install TL on a Win10 machine failed because I
keep getting errors of that kind:

--- from install-tl.log ---
Installing [1168/4168, time/total: 40:38/02:31:27]: easybook [729k]
TeXLive::TLUtils::check_file_and_remove: checksums differ for C:\Users\siart\AppData\Local\Temp\isGcN_ZygU\KzgDREODqS/easybook.tar.xz:
TeXLive::TLUtils::check_file_and_remove:   tlchecksum=336079c50a5def89f69d36f5ad8028de23c1786015cc538d687cbaea16be6ee39cffd28de1de2fa414d1956c6fbe262a0a7820b9c1d4ee0713f6d9bf3e2142f6, arg=083d39399aa79f7989b78cee64fa7d90249efa39e8f4201ce4aeb28fd674b3bfc6a5acf222beec50d11638c70cf505f16df4d5330475baba68e55a210c017fff
TeXLive::TLUtils::check_file_and_remove: backtrace:
 -> E:/org/incoming/install-tl-20210504/tlpkg/TeXLive/TLUtils.pm:2342: TeXLive::TLUtils::check_file_and_remove
 -> E:/org/incoming/install-tl-20210504/tlpkg/TeXLive/TLPDB.pm:1976: TeXLive::TLUtils::unpack
 -> E:/org/incoming/install-tl-20210504/tlpkg/TeXLive/TLPDB.pm:1811: TeXLive::TLPDB::_install_data
 -> E:/org/incoming/install-tl-20210504/tlpkg/TeXLive/TLPDB.pm:1727: TeXLive::TLPDB::not_virtual_install_package
 -> E:/org/incoming/install-tl-20210504/tlpkg/TeXLive/TLUtils.pm:1556: TeXLive::TLPDB::install_package
 -> E:/org/incoming/install-tl-20210504/install-tl:2135: TeXLive::TLUtils::install_packages
 -> E:/org/incoming/install-tl-20210504/install-tl:946: main::do_install_packages
 -> E:/org/incoming/install-tl-20210504/install-tl:700: main::do_installation
TeXLive::TLUtils::check_file_and_remove:   removing C:\Users\siart\AppData\Local\Temp\isGcN_ZygU\KzgDREODqS/easybook.tar.xz, but saving copy in C:\Users\siart\AppData\Local\Temp\kWQ4LmFxvw
TLPDB::_install_data: downloading did not succeed (check_file_and_remove failed) for https://www.ctan.org/tex-archive/systems/texlive/tlnet/archive/easybook.tar.xz
TLUtils::install_packages: Failed to install easybook
                           easybook will be retried later.
---------------------------

The retry at the end fails as well and so the entire install fails:

--- from install-tl.log ---
Retrying to install: easybook [729k]
TeXLive::TLUtils::check_file_and_remove: checksums differ for C:\Users\siart\AppData\Local\Temp\isGcN_ZygU\2j3EFdG5Sk/easybook.tar.xz:
TeXLive::TLUtils::check_file_and_remove:   tlchecksum=336079c50a5def89f69d36f5ad8028de23c1786015cc538d687cbaea16be6ee39cffd28de1de2fa414d1956c6fbe262a0a7820b9c1d4ee0713f6d9bf3e2142f6, arg=083d39399aa79f7989b78cee64fa7d90249efa39e8f4201ce4aeb28fd674b3bfc6a5acf222beec50d11638c70cf505f16df4d5330475baba68e55a210c017fff
TeXLive::TLUtils::check_file_and_remove: backtrace:
 -> E:/org/incoming/install-tl-20210504/tlpkg/TeXLive/TLUtils.pm:2342: TeXLive::TLUtils::check_file_and_remove
 -> E:/org/incoming/install-tl-20210504/tlpkg/TeXLive/TLPDB.pm:1976: TeXLive::TLUtils::unpack
 -> E:/org/incoming/install-tl-20210504/tlpkg/TeXLive/TLPDB.pm:1811: TeXLive::TLPDB::_install_data
 -> E:/org/incoming/install-tl-20210504/tlpkg/TeXLive/TLPDB.pm:1727: TeXLive::TLPDB::not_virtual_install_package
 -> E:/org/incoming/install-tl-20210504/tlpkg/TeXLive/TLUtils.pm:1576: TeXLive::TLPDB::install_package
 -> E:/org/incoming/install-tl-20210504/install-tl:2135: TeXLive::TLUtils::install_packages
 -> E:/org/incoming/install-tl-20210504/install-tl:946: main::do_install_packages
 -> E:/org/incoming/install-tl-20210504/install-tl:700: main::do_installation
TeXLive::TLUtils::check_file_and_remove:   removing C:\Users\siart\AppData\Local\Temp\isGcN_ZygU\2j3EFdG5Sk/easybook.tar.xz, but saving copy in C:\Users\siart\AppData\Local\Temp\F2MTLbLyY0
TLPDB::_install_data: downloading did not succeed (check_file_and_remove failed) for https://www.ctan.org/tex-archive/systems/texlive/tlnet/archive/easybook.tar.xz
Installation failed.
Rerunning the installer will try to restart the installation.
Or you can restart by running the installer with:
  install-tl-windows.bat --profile installation.profile [YOUR-EXTRA-ARGS]
or
  install-tl-advanced.bat --profile installation.profile [YOUR-EXTRA-ARGS]
---------------------------

Since I don't see what I'm doing wrong I wanted to let you know. At the
moment I'm kind of desperate and I don't see a solution.

-- 
Uwe