ipv6 accept_ra

[Lee <ler762@gmail.com>]

I have a desktop and a laptop - neither one is picking up the ipv6
network prefix from the router advertisement.  'ifconfig -a' on both
show a single 'inet6 fe80::' line under each interface.

if it makes a difference:
$ cat /etc/debian_version
11.3

I checked with wireshark - the RAs look good.
After some searching I came across this

https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt
accept_ra - INTEGER
	Accept Router Advertisements; autoconfigure using them.

	It also determines whether or not to transmit Router
	Solicitations. If and only if the functional setting is to
	accept Router Advertisements, Router Solicitations will be
	transmitted.

	Possible values are:
		0 Do not accept Router Advertisements.
		1 Accept Router Advertisements if forwarding is disabled.
		2 Overrule forwarding behaviour. Accept Router Advertisements
		  even if forwarding is enabled.

	Functional default: enabled if local forwarding is disabled.
			    disabled if local forwarding is enabled.

local forwarding is disabled
$ sysctl -a 2>/dev/null | grep ipv6 | grep 'forwarding '
net.ipv6.conf.all.forwarding = 0
net.ipv6.conf.all.mc_forwarding = 0
net.ipv6.conf.default.forwarding = 0
net.ipv6.conf.default.mc_forwarding = 0
net.ipv6.conf.enp1s0.forwarding = 0
net.ipv6.conf.enp1s0.mc_forwarding = 0
net.ipv6.conf.lo.forwarding = 0
net.ipv6.conf.lo.mc_forwarding = 0
net.ipv6.conf.wlp2s0.forwarding = 0
net.ipv6.conf.wlp2s0.mc_forwarding = 0

but so is accept_ra
$ sysctl -a 2>/dev/null | grep 'accept_ra '
net.ipv6.conf.all.accept_ra = 1
net.ipv6.conf.default.accept_ra = 1
net.ipv6.conf.enp1s0.accept_ra = 0
net.ipv6.conf.lo.accept_ra = 1
net.ipv6.conf.wlp2s0.accept_ra = 0

How do I get the default "accept_ra = 1" set on _all_ interfaces?

TIA,
Lee