Where/how to report general routing problem?

[#1]

For those who may be interested there are 10 domains registered to 195.225.31.64 (web.colorline.basefarm.net)

colorline.no
colorline.com
colorline.de
colorline.nl
colorline.dk
colorline.se
skagenhotel.dk
colorline-cargo.com
colorlineferries.nl
skagenhotel.com

Regarding trace route it uses ICMP by default so unless the device responds to ping it will not display the complete route,
you can get around this issue in linux by adding -T switch and execute using sudo or as a root user. The switch -T is to test using TCP SYN on port 80 rather than ICMP

sudo traceroute -T www.colorline.com

linux mtr users can also add -T (-b added to include IP and hostname to the results).
mtr -T -b -r -w -c 1 www.colorline.com

demouser@desktop-mate:~$ mtr -T -b -r -w -c 1 www.colorline.com
Start: 2023-09-04T08:57:06+0100
HOST: desktop-mate Loss% Snt Last Avg Best Wrst StDev
1.|-- _gateway (192.168.10.1) 0.0% 1 4.0 4.0 4.0 4.0 0.0
2.|-- 195.166.130.249 0.0% 1 10.9 10.9 10.9 10.9 0.0
3.|-- gi2-23-442.ptn-gw02.plus.net (84.93.253.75) 0.0% 1 12.0 12.0 12.0 12.0 0.0
4.|-- 195.99.125.136 0.0% 1 12.1 12.1 12.1 12.1 0.0
5.|-- core5-hu0-7-0-15.faraday.ukcore.bt.net (195.99.127.36) 0.0% 1 16.3 16.3 16.3 16.3 0.0
6.|-- 166-49-214-194.gia.bt.net (166.49.214.194) 0.0% 1 12.0 12.0 12.0 12.0 0.0
7.|-- ldn-b13-link.ip.twelve99.net (62.115.148.100) 0.0% 1 15.1 15.1 15.1 15.1 0.0
8.|-- ldn-bb1-link.ip.twelve99.net (62.115.120.74) 0.0% 1 20.7 20.7 20.7 20.7 0.0
9.|-- hbg-bb3-link.ip.twelve99.net (80.91.249.11) 0.0% 1 40.8 40.8 40.8 40.8 0.0
10.|-- oso-b1-link.ip.twelve99.net (62.115.112.85) 0.0% 1 37.9 37.9 37.9 37.9 0.0
11.|-- basefarm-ic-306597.ip.twelve99-cust.net (62.115.45.130) 0.0% 1 41.0 41.0 41.0 41.0 0.0
12.|-- vcore01-onramp.osl.basefarm.net (109.68.93.13) 0.0% 1 40.9 40.9 40.9 40.9 0.0
13.|-- oslv-lb01b-v2396.osl.basefarm.net (195.225.14.142) 0.0% 1 38.8 38.8 38.8 38.8 0.0
14.|-- web.colorline.basefarm.net (195.225.31.64) 0.0% 1 39.1 39.1 39.1 39.1 0.0

@Greg60  I know this post doesn't help you but it may help others.

I note @bobpullen  has already commented on this thread.

[#2]

On the off chance that somebody might be reading email (what a thought!), I emailed the contact in the RIPE database for the destination network, and got a reply.  They confirmed they had been mitigating multiple attacks over the past couple of weeks, including from my subnet, but that things were now back to normal.  I cannot help ponder over this:

Plusnet: my provider, gets paid, impossible to contact, hosts bots/attackers, presumably ignores comms from other providers

webhost: no relationship, responds promptly and courteously to email

Many thanks to everybody who tried to help.