nginx as a reverse proxy looses cookies - asp.net-core

Question

I'm trying to setup an nginx as a reverse proxy for my web app.
The scheme:
nginx on a server host receives requests and transfers them to another host
nginx works as a HTTPS (wildcard certificate used globally), web app as a HTTP
at this stage i don't need nginx caching (at least while trying to figure out how to make it work)
nginx redirects all HTTP traffic to HTTPS
nginx blocks hostless requests
Here is a config:
worker_processes 1;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
sendfile on;
keepalive_timeout 65;
ssl_certificate ./certs/my_domain.crt;
ssl_certificate_key ./certs/my_domain.key;
ssl_prefer_server_ciphers on;
ssl_session_cache shared:SSL:10m;
ssl_session_timeout 10m;
add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
server {
listen 80;
return 444;
}
server {
listen 80;
server_name my_domain.com www.my_domain.com *.my_domain.com;
return 301 https://$host$request_uri;
}
server {
listen 443 ssl;
server_name my_domain.com;
location / {
root html;
index index.html index.htm;
}
}
server {
listen 443 ssl;
server_name expert.my_domain.com;
location / {
proxy_pass http://192.168.0.83:50000;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection keep-alive;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
}
}
}
While viewing nginx docs i've noticed that caching has to be turned on explicitly (proxy_cache off by default). But i'm not sure if there is something else has to be done to turn it off completely.
The sequence:
log in to the web app through nginx
authorize and get a cookie
open a second tab with the app
get a cookie from step (2)
refresh the page
loose a cookie (??)
Here is the results after step (3):
Request Method: GET
Request Scheme: https
Request Path: /
Request Headers:
Connection: keep-alive
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Accept-Encoding: gzip, deflate, br
Accept-Language: ru-RU,ru;q=0.9,en-US;q=0.8,en;q=0.7,ky;q=0.6
Cookie: .AspNetCore.Identity.Application=*** LONG ASP NET CORE IDENTITY COOKIE ***
Host: expert.my_domain.com
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.116 Safari/537.36
Upgrade-Insecure-Requests: 1
X-Original-Proto: http
X-Real-IP: 192.168.0.83
Sec-Fetch-Site: cross-site
Sec-Fetch-Mode: navigate
Sec-Fetch-User: ?1
Sec-Fetch-Dest: document
X-Original-For: [::ffff:192.168.0.12]:54035
The cookie and stuff is there.
And here is how it looks like after simple refresh:
Request Method: GET
Request Scheme: https
Request Path: /
Request Headers:
Cache-Control: max-age=0
Connection: keep-alive
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Accept-Encoding: gzip, deflate, br
Accept-Language: ru-RU,ru;q=0.9,en-US;q=0.8,en;q=0.7,ky;q=0.6
Host: expert.my_domain.com
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.116 Safari/537.36
Upgrade-Insecure-Requests: 1
X-Original-Proto: http
X-Real-IP: 192.168.0.83
Sec-Fetch-Site: cross-site
Sec-Fetch-Mode: navigate
Sec-Fetch-User: ?1
Sec-Fetch-Dest: document
X-Original-For: [::ffff:192.168.0.12]:54038
Notice the absence of cookie part.
I believe this has something to do with caching. Seems that after opening the page in another tab, browser (chrome in this case) shows me a cached version where cookie is present. Not sure who caches it though - nginx or chrome. And after that whoosh and it's gone.
Why i think this is an issue with nginx? When doing the same thing with the app directly there are no problems of any kind. It fully works as expected.
What could be missing here? Is caching problem involved? How to completely disable caching with nginx?