Error connecting to virtual server (HTTP header count exceeded)

I have a new pre-prod HTTPS virtual server. One server in the pool, passing health checks, and the virtual server has zero iRules associated to it.

When I run a curl request to the virtual server, the LTM log is returning errors.

curl --location --request GET 'https://10.10.10.10:443' \
--header 'Host: app.example.com'
curl: (56) LibreSSL SSL_read: SSL_ERROR_SYSCALL, errno 54

I get a successful response from the F5 to the back-end server.

Running version 13.1.3.4.