unable to POST due to http -> https

for some reason my POST request keeps returning 307 redirect.

Request URL: https://*****.dev/chat/respond
Request Method: POST
Status Code: 307 
Referrer Policy: strict-origin-when-cross-origin

my suspicion is seeing this in the POST response headers:
location: http://****.dev/chat/respond/
and the URL that HTML is rendered is:

but what causes this? the request is a full path to the https route, the page itself is rendered in https

I am using FastAPI, and i am not sure what information I could provide to help the debugging process
Here is how i serve the text.html file
app.mount("/static", StaticFiles(directory="static"), name="static")

my fly.toml

# fly.toml file generated for dachi-app on 2023-02-16T12:44:18-08:00

app = "dachi-app"
kill_signal = "SIGINT"
kill_timeout = 5
processes = []


  auto_rollback = true

  http_checks = []
  internal_port = 8080
  processes = ["app"]
  protocol = "tcp"
  script_checks = []
    hard_limit = 25
    soft_limit = 20
    type = "connections"

    force_https = true
    handlers = ["http"]
    port = 80

    handlers = ["tls", "http"]
    port = 443

    grace_period = "1s"
    interval = "15s"
    restart_limit = 0
    timeout = "2s"