I know this is a little old, and maybe you figured it out already, but do you still have to designate the reverse proxy as trusted via your configuration.yaml file in home assistant? I forgot about that change to HA where you need to set 'use_x_forwarded_for' to 'true' and list the reverse proxy by IP under the http: config. Kind of like the below maybe?
http:
use_x_forwarded_for: true
trusted_proxies:
- 172.30.33.4 #or whatever your proxy is
ip_ban_enabled: true
login_attempts_threshold: 5