ALPN negotiation not working with generate-certificates

I’m using haproxy as a main in the middle proxy where I generate certificates with the generate-certificates line. My bind file is also using the crt-list, which I’ve tried adding the [ alpn h2,http/1.1 ] to the cert that is used to generate the certs, but still does not work. If I use a regular certificate that doesn’t need to generate anything, the ALPN negotiation works fine, it’s only domains where I do the certificate generation that fail ALPN. This is causing H2 connections to fail through the proxy. I’m curious if this is a known issue, or anyone has any suggestions for a work around.

bind *:443 ssl crt-list /etc/haproxy/certs/crt-list ca-sign-file /etc/certs/mount/combined.pem generate-certificates alpn h2,http/1.1

HAProxy version 2.4.16-1ppa1~focal 2022/04/29 - https://haproxy.org/
Status: long-term supported branch - will stop receiving fixes around Q2 2026.
Known bugs: http://www.haproxy.org/bugs/bugs-2.4.16.html
Running on: Linux 5.4.0-1096-fips #106-Ubuntu SMP Fri Mar 15 19:31:31 UTC 2024 x86_64
Build options :
  TARGET  = linux-glibc
  CPU     = generic
  CC      = cc
  CFLAGS  = -O2 -g -O2 -fdebug-prefix-map=/build/haproxy-rRziWI/haproxy-2.4.16=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -Wall -Wextra -Wdeclaration-after-statement -fwrapv -Wno-address-of-packed-member -Wno-unused-label -Wno-sign-compare -Wno-unused-parameter -Wno-clobbered -Wno-missing-field-initializers -Wno-cast-function-type -Wtype-limits -Wshift-negative-value -Wshift-overflow=2 -Wduplicated-cond -Wnull-dereference
  OPTIONS = USE_PCRE2=1 USE_PCRE2_JIT=1 USE_OPENSSL=1 USE_LUA=1 USE_SLZ=1 USE_SYSTEMD=1 USE_PROMEX=1
  DEBUG   =

Feature list : +EPOLL -KQUEUE +NETFILTER -PCRE -PCRE_JIT +PCRE2 +PCRE2_JIT +POLL -PRIVATE_CACHE +THREAD -PTHREAD_PSHARED +BACKTRACE -STATIC_PCRE -STATIC_PCRE2 +TPROXY +LINUX_TPROXY +LINUX_SPLICE +LIBCRYPT +CRYPT_H +GETADDRINFO +OPENSSL +LUA +FUTEX +ACCEPT4 -CLOSEFROM -ZLIB +SLZ +CPU_AFFINITY +TFO +NS +DL +RT -DEVICEATLAS -51DEGREES -WURFL +SYSTEMD -OBSOLETE_LINKER +PRCTL -PROCCTL +THREAD_DUMP -EVPORTS -OT -QUIC +PROMEX -MEMORY_PROFILING

Default settings :
  bufsize = 16384, maxrewrite = 1024, maxpollevents = 200

Built with multi-threading support (MAX_THREADS=64, default=16).
Built with OpenSSL version : OpenSSL 1.1.1f  31 Mar 2020
Running on OpenSSL version : OpenSSL 1.1.1f  31 Mar 2020
OpenSSL library supports TLS extensions : yes
OpenSSL library supports SNI : yes
OpenSSL library supports : TLSv1.0 TLSv1.1 TLSv1.2 TLSv1.3
Built with Lua version : Lua 5.3.3
Built with the Prometheus exporter as a service
Built with network namespace support.
Built with libslz for stateless compression.
Compression algorithms supported : identity("identity"), deflate("deflate"), raw-deflate("deflate"), gzip("gzip")
Built with transparent proxy support using: IP_TRANSPARENT IPV6_TRANSPARENT IP_FREEBIND
Built with PCRE2 version : 10.34 2019-11-21
PCRE2 library supports JIT : yes
Encrypted password support via crypt(3): yes
Built with gcc compiler version 9.4.0

Available polling systems :
      epoll : pref=300,  test result OK
       poll : pref=200,  test result OK
     select : pref=150,  test result OK
Total: 3 (3 usable), will use epoll.

Available multiplexer protocols :
(protocols marked as <default> cannot be specified using 'proto' keyword)
              h2 : mode=HTTP       side=FE|BE     mux=H2       flags=HTX|CLEAN_ABRT|HOL_RISK|NO_UPG
            fcgi : mode=HTTP       side=BE        mux=FCGI     flags=HTX|HOL_RISK|NO_UPG
       <default> : mode=HTTP       side=FE|BE     mux=H1       flags=HTX
              h1 : mode=HTTP       side=FE|BE     mux=H1       flags=HTX|NO_UPG
       <default> : mode=TCP        side=FE|BE     mux=PASS     flags=
            none : mode=TCP        side=FE|BE     mux=PASS     flags=NO_UPG

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Available filters :
        [SPOE] spoe
        [CACHE] cache
        [FCGI] fcgi-app
        [COMP] compression
        [TRACE] trace