It would appear the reason I have this error is because I am using
Joomla SEF URLs and not the Seblod router ones. I must use Joomla SEF as
I use SH404SEF. Actually I am migrating my website from Flexicontent to
Seblod and I need to use SH404SEF to control URL generation for SEO
reasons.
It is the same issue as discussed here:
https://www.seblod.com/community/forums/general-discussions/competibility
Will
the compatibility of Joomla Native SEF URL generation with Seblod be
addressed? Issue will happen in all cases with SEF url generation off,
regardless of SEF URL configuration settings. This is an issue with
Seblod and Joomla routing.
As a workaround I can replace URLs
in SH404SEF with versions not including the itemid=101. This workaround
does work, but it is very much not ideal. I can workaround the issue by
creating a Joomla native Category menu item (Add menu -> Articles
-> Category list), which will be a workaround suitable for most
content types, and fortunately for the content type I need with specific
menu structure it will only be maintained by me, so the workaround is
suitable.
Cheers,
Nick