Kernel parameters described in /etc/sysctl.conf are not reflected after reboot

Issue

We see our settings in /etc/sysctl.conf ignored. We have this in /etc/sysctl.conf:

net.ipv4.conf.all.forwarding=0' >/etc/sysctl.conf
net.ipv4.conf.default.forwarding=0' >>/etc/sysctl.conf

When then executing sysctl -p, we see that these are set correctly:

[root@rhel8u4a ~]# sysctl -a | egrep 'net.ipv4.conf.all.forwarding|net.ipv4.conf.default.forwarding'
net.ipv4.conf.all.forwarding = 0
net.ipv4.conf.default.forwarding = 0

However, after restart of the system, we see that both sysctl are set to 1:

[root@rhel8u4a ~]# sysctl -a | egrep 'net.ipv4.conf.all.forwarding|net.ipv4.conf.default.forwarding'
net.ipv4.conf.all.forwarding = 1
net.ipv4.conf.default.forwarding = 1

These unexpected sysctls are seen on systems with package group @graphical-server-environment installed.