Comment # 4 on bug 1158817 from Matthew Gibbs

I had a similar issue, but in my case I had been using the lines

net.bridge.bridge-nf-call-ip6tables = 0
net.bridge.bridge-nf-call-iptables = 0

in sysctl.conf to have bridge traffic bypass firewalld.

After updating last night, it appeared that the settings were being ignored
when booting.  If I called e.g. echo "0" >
/proc/sys/net/bridge/bridge-nf-call-iptables then things started working again
until another reboot.

I have suse-module-tools-15.1.18-lp151.2.4.1

Commenting out the cited line does fix the issue for me, too, and also
eliminates the need for the above configuration.

It was quite a surprise to find things not working and not easy to track down
the cause.