Can't change size of types_hash_max_size

Currently I'm trying to setup a nextcloud server with nginx. Now I've the following in my /etc/nginx/sites-available/nextcloud.conf:

server {
    listen 443 ssl;
    server_name localhost;

    (...) 
    types_hash_bucket_size 8192;
    types_hash_max_size 8192;
    ssl_certificate /nextcloud/certification/nextcloud.csr;
    ssl_certificate_key /nextcloud/certification/nextcloud.key;
    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
    (...)

    # logging
    access_log /nextcloud/access.log;
    error_log /nextcloud/error.log info;

}

And this is in my /etc/nginx/nginx.conf:

(...)
http {
    include       mime.types;
    default_type  application/octet-stream;

    server_names_hash_bucket_size 8192;

    # include all enabled servers!
    include sites-enabled/*;
    (...)
}

I created a soft link from /etc/nginx/sites-available/nextcloud.conf to /etc/nginx/sites-enabled/nextcloud.conf so it should be loaded. Anyway I'm getting this error, when I'm running this command nginx -t:

2020/11/06 16:05:43 [warn] 249785#249785: could not build optimal types_hash, you should increase either types_hash_max_size: 1024 or types_hash_bucket_size: 64; ignoring types_hash_bucket_size

I'm wondering why I'm getting this although I've set it to 8192?
I created the as mentioned in from the answer link of this post. So that's the command how I created the key:

openssl req -newkey rsa:4096 -nodes -keyout nextcloud.key -out nextcloud.csr

I've already tried to set types_hash_bucket_size and types_hash_max_size to 4096 but that doesn't change anything either. What am I doing wrong?