How to run container as non-root? And problems with fetching articles and WebGUI.

I have tried to deploy the container on a synology NAS for couple of hours.
Finally got it going but I had to deploy it with root and no user ID or group ID parameters at all.

I also get a few other problems. I SSH in to my container as root and run:

docker run -d --name Wallabag --restart always --link MariaDB:wallabag-db
-e MYSQL_ROOT_PASSWORD=pass
-e SYMFONY__ENV__DATABASE_DRIVER=pdo_mysql
-e SYMFONY__ENV__DATABASE_HOST=MariaDB
-e SYMFONY__ENV__DATABASE_PORT=3306
-e SYMFONY__ENV__DATABASE_NAME=wallabag
-e SYMFONY__ENV__DATABASE_USER=wallabag
-e SYMFONY__ENV__DATABASE_PASSWORD=pass
-e SYMFONY__ENV__DATABASE_CHARSET=utf8mb4
-e SYMFONY__ENV__SECRET=secret
-e SYMFONY__ENV__DOMAIN_NAME=https://wallabag.mydomain.com
-e SYMFONY__ENV__FOSUSER_CONFIRMATION=false
-e SYMFONY__ENV__FOSUSER_REGISTRATION=true
-v /volume1/docker/Wallabag/data:/var/www/wallabag/data
-v /volume1/docker/Wallabag/images:/var/www/wallabag/web/assets/images
-p 1420:80
wallabag/wallabag

The MariaDB is the linuxserver container. I realise after reading some that I did not actually specify utf8mb4 in that container in any way. That environment variable was not defined in there wiki and Im kinda noob.. I just follow tutorials.. Should I do something there?

In my haproxy reverse proxy config I have bunch of configs which all work great. On several other containers.
This one I just pointed to the http port of wallabag and thats it. I seem to reach the site and login/create account and API etc..

However the viewing experience in the wallabag http gui is awful. Sometimes fonts just double up on eachother. If I delete a article I get error: 404: Not Found
Wallabag\CoreBundle\Entity\Entry object not found.

Some articles dont fetch at all.. I tried the f-droid app on my android and that seemed to work fine. But on my firefox on linuxdesktop with wallabagger addon I get these unfetchable entries in wallabag.

I didnt find any log or anything at all in the docker folder. Maybe I didnt mount it? Couldn't find anything about how to mount log directory in the wiki. But in my synology docker log for the container I see bunch of these:

2020/01/05 23:05:27 [error] 275#275: *339 FastCGI sent in stderr: "PHP message: PHP Warning: "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"? in /var/www/wallabag/vendor/doctrine/orm/lib/Doctrine/ORM/UnitOfWork.php on line 2636PHP message: PHP Warning: "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"? in /var/www/wallabag/vendor/doctrine/orm/lib/Doctrine/ORM/UnitOfWork.php on line 2665" while reading response header from upstream, client: 172.17.0.1, server: _, request: "GET /delete/6 HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "wallabag.domain.com", referrer: "https://wallabag.mydomain.com/delete/6"

Just spamming it in the logs..

Could anyone please help a noob like me understand whats wrong? Thanks!