Rudder

It looks like automatic allowed network detection severely failed. What do you see in the settings page, in the allowed networks section?

The list of networks is parsed from LANG=C ip -family inet -oneline address and LANG=C ip -family inet6 -oneline address outputs, what does it give on your machine? (you can anonymize IPs, it is probably a unexpected format somewhere). We also need to check the detected networks before inserting them.

here the output of the above mentioned ip command (with blanked ip addresses):

LANG=C ip -family inet -oneline address
1: lo inet 127.0.0.1/8 scope host lo\ valid_lft forever preferred_lft forever
2: ens18 inet <my_ip_v4>/<mask> brd <my_ip_v4_broadcast_addr> scope global ens18\ valid_lft forever preferred_lft forever

LANG=C ip -family inet6 -oneline address
1: lo inet6 ::1/128 scope host \ valid_lft forever preferred_lft forever
2: ens18 inet6 <my_ip_v6>/<mask> scope global dynamic mngtmpaddr \ valid_lft 604790sec preferred_lft 86390sec
2: ens18 inet6 <my_ip_v6_link_local>/<mask> scope link \ valid_lft forever preferred_lft forever

(piped through od -a tells me all blanks are spaces not tabs)

and attached a partial screenshot from the GUI settings page (blanked fields are hostname, ipv4/mask, ipv6/mask - all three correct though)
... ups, no, seems upload don't allow .png files?

Well under "Allowed networks ..." in the GUI I have 14 fields with the following content(by row):

- correct ipv4
- 2:
- ens18

- inet6
- correct ipv6
- scope

- global
- dynamic
- mngtmpaddr

- \ndirectiveVariable: ALLOWEDNETWORK¹⁰:valid_lft
- an empty field
- 604793sec

- preferred_lft
- 86393sec

from "man ip" I get:
...
-o, -oneline
output each record on a single line, replacing line feeds with the '\' character. This is convenient when you want to count records with wc(1) or to grep(1) the output.

...