As discussed on Kali Discord, the Kali mirror in NL (nluug.nl) is always out of sync for the past 3 weeks.
A snippet from my Gitlab CI/CD for Kali i3-gaps:
P: Deconfiguring file /etc/apt/sources.list
Get:1 http://packages.microsoft.com/repos/code stable InRelease [10.4 kB]
Get:2 http://packages.microsoft.com/repos/code stable/main armhf Packages [104 kB]
Get:3 http://packages.microsoft.com/repos/code stable/main arm64 Packages [104 kB]
Get:4 http://packages.microsoft.com/repos/code stable/main amd64 Packages [103 kB]
Get:5 http://packages.microsoft.com/repos/code stable/main armhf Contents (deb) [54.6 kB]
Get:6 http://packages.microsoft.com/repos/code stable/main amd64 Contents (deb) [54.6 kB]
Get:7 http://packages.microsoft.com/repos/code stable/main arm64 Contents (deb) [54.6 kB]
Get:8 http://ftp2.nluug.nl/os/Linux/distr/kali kali-rolling InRelease [30.6 kB]
Get:9 http://ftp2.nluug.nl/os/Linux/distr/kali kali-rolling/contrib Sources [70.9 kB]
Get:10 http://ftp2.nluug.nl/os/Linux/distr/kali kali-rolling/non-free Sources [129 kB]
Get:11 http://ftp2.nluug.nl/os/Linux/distr/kali kali-rolling/main Sources [14.7 MB]
Get:12 http://ftp2.nluug.nl/os/Linux/distr/kali kali-rolling/main amd64 Packages [18.3 MB]
Get:13 http://ftp2.nluug.nl/os/Linux/distr/kali kali-rolling/main amd64 Contents (deb) [42.5 MB]
Ign:13 http://ftp2.nluug.nl/os/Linux/distr/kali kali-rolling/main amd64 Contents (deb)
Get:14 http://ftp2.nluug.nl/os/Linux/distr/kali kali-rolling/contrib amd64 Packages [108 kB]
Get:15 http://ftp2.nluug.nl/os/Linux/distr/kali kali-rolling/contrib amd64 Contents (deb) [155 kB]
Ign:15 http://ftp2.nluug.nl/os/Linux/distr/kali kali-rolling/contrib amd64 Contents (deb)
Get:16 http://ftp2.nluug.nl/os/Linux/distr/kali kali-rolling/non-free amd64 Packages [224 kB]
Get:17 http://ftp2.nluug.nl/os/Linux/distr/kali kali-rolling/non-free amd64 Contents (deb) [952 kB]
Ign:13 http://http.kali.org/kali kali-rolling/main amd64 Contents (deb)
Ign:15 http://http.kali.org/kali kali-rolling/contrib amd64 Contents (deb)
Err:13 http://http.kali.org/kali kali-rolling/main amd64 Contents (deb)
File has unexpected size (42413639 != 42469362). Mirror sync in progress? [IP: 145.220.21.40 80]
Ign:15 http://http.kali.org/kali kali-rolling/contrib amd64 Contents (deb)
Fetched 35.0 MB in 7s (4716 kB/s)
Reading package lists...
E: Failed to fetch http://http.kali.org/kali/dists/kali-rolling/main/Contents-amd64 File has unexpected size (42413639 != 42469362). Mirror sync in progress? [IP: 145.220.21.40 80]
Given the frequency of this issue, I personally believe nluug.nl needs to be removed as a mirror or replaced with an alternative mirror. | 
