Problem with lets encrypt and redirect after update

Hi,

we have updated our BigIP last week from 15.x to 17.1.1.4, since then we are not able to get certificates from lets encrypt, if there is the _sys_https_redirect iRule active on the Virtual Server.

As an example, i have for the IP 1.2.3.4 (asdf123.info) two VS with port 80 and 443, on port 80 are two iRules mapped:

lets_encrypt:

when HTTP_REQUEST {
        if {[HTTP::has_responded]} {return}

        if { not ([HTTP::path] starts_with "/.well-known/acme-challenge/") } { return }
		set token [lindex [split [HTTP::path] "/"] end]
		set response [class match -value -- $token equals acme_responses]
		if { "$response" == "" } {
			log local0. "Responding with 404 to ACME challenge $token"
			HTTP::respond 404 content "Challenge-response token not found."
		} else {
			log local0. "Responding to ACME challenge $token with response $response"
			HTTP::respond 200 content "$response" "Content-Type" "text/plain; charset=utf-8"
		}
	}

and _sys_https_redirect:

# Copyright 2003-2006, 2012-2013, 2016, 2019.  F5 Networks, Inc.  See End User License Agreement ("EULA")
# for license terms. Notwithstanding anything to the contrary in the EULA,
# Licensee may copy and modify this software product for its internal business
# purposes. Further, Licensee may upload, publish and distribute the modified
# version of the software product on devcentral.f5.com.
#
    when HTTP_REQUEST {
       HTTP::redirect https://[getfield [HTTP::host] ":" 1][HTTP::uri]
    }
definition-signature tJY87UPbfpgQ3TPXqXhbCAgqIJhR1MvyFxXLTX/wNqmH+XV51tNkr8HWmv4PBq8hm6w7peLKj88shG+0RiX+yAMU31n6jS9vRcg0VKNPBWLTzu3Ic8abqyyY6XYgkMel+d9Sa8x+vakcuPcAZ0dnICHQiQFePjxYUD0XKwIrbGqQb8vEcU3HHbDaLoMQry4KDnV3s1crFpWXBZBo6esIdzM/s0jYncqZBNdTmIEH3ujEunmo2Jh9MBDhwfGKy1XwCfeeZvzk8b1J+HbRk7W/vbrRUewJZDt+Z13i9u/MbneAL4QXZgtjSxU2nN4GcZjWePUIm7oxc1nz9FGeNva1xg==

This configuration had worked for years now, but since the update to 17.1.1.4 we get a "connection reset by peer" at requests for http://asdf123.info/.well-known/acme-challenge/30IpwjJqyA7LKANXCvu7gyN9txfYQOqzllBNC3ROPnY

if i remove the _sys_https_redirect iRule, it works fine. 

Has anyone an solution for this problem?