Post installation

After migration from a drupal 7 site to a D9 version I get this warning on every cache clear command.
Tried to dsm the routes in the routebuilder to see if there is a non-object or non-array but cannot see anything wrong. The site also behaves ok.

(later redaction) This error only occurs in the docker container, not on the server. (end)

Question
Anyone has an idea what causes this?

I see that Drupal 10 chose Olivero as default Theme. It looks ok, however I have an issue on mobile display.
I am running blog and using Side Bar. It is ok on desktop display but on mobile, the Side Bar is not narrow and displaying in full wide.

Please advise if can change some settings for mobile support.

Before, I used Bartik Theme and it was ok. I would prefer to see if can use newer Theme, like Olivero. or if you have any other recommended Theme for blog.

So I got my first drupal site up after a little rough patch. Now Iam working on setting things up but then I logged in at first its fine, but when I choose any option from the menu lets say content.

The page loads but says access denied, however if I simply refresh the browser the content page is there. Then I choose ad content or edit an already created content item and save , I get the access denied again.

Hello,

I'm using taxonomy terms to structure my content. On taxonomy is related to 4 content types.

Currently, I have this URL structure:

url.com/parent-term/term

There, I use layout builder to .. well, build the layout for the terms, works amazing!

For those 4 related content types, I'd like to use:

• URL paths that make sense
• layout builder as well

url.com/parent-term/term/content_type1
url.com/parent-term/term/content_type2
...

Problem 1:

in order to make my site more secured, I followed this very helpful Drupal's doc:
https://www.drupal.org/docs/administering-a-drupal-site/security-in-drup...

It is comprehensive and clear, however, I have one issue: My setup is home site, based on: Raspberry PI3B, operating system is smc (linux, debian), nginx. Composer installation of Drupal 10 drupal/core-recommended.

This question concerns using the Redirect Module: https://www.drupal.org/project/redirect

Hello forum, this is my first effort using the forum to field a specific question.  Hoping someone who reads this knows a bit about the redirect module.  I'm not 100% sure I'm using it correctly -- so before I post in their specific pages.. I thought I'd ask here and see if someone knows the answer first.

Background info: