Bad address for ipv6 only CNAME in 23.05

I have two OpenWrt devices pc engines apu4 (x86) that I updated to 23.05. I'm not 100% sure if it started occuring after the update but I have problems contacting a specific host that I need for acme dns challenge. The garget host is running a powerdns API which I have configured as target URL:

# Configuration generated by Ansible
config acme
        option state_dir "/etc/acme"
        option debug "0"
        option account_email "jochen@example.com"

config cert "maincert"
        option keylength "4096"
        list domains "apukeller.example.com"
        option validation_method "dns"
        option dns "dns_pdns"
        list credentials 'PDNS_ServerId=localhost'
        list credentials 'PDNS_Ttl=60'
        list credentials 'PDNS_Url="https://dnsapi.example.com"'
        list credentials 'PDNS_Token="thisIsASecret"'
        option enabled "1"
        option use_staging "0"
        option update_uhttpd "1"

Eversince the update I cannot contact dnsapi.example.com any more. It seems somehow to be related to DNS. dnsapi.example.com is a CNAME for hostA.example.com. hostA.example.com only resolves to a ULA IPv6 address (fd01:4dd0:28d4:5000::13). I have verified that it actually works but on the OpenWrt devices it seems somehow broken.
If I ping dnsapi.example.com or cname.example.com in both cases I get

ping: bad address 'hostA.exmaple.com'

My ipv6 connectivity is fully working.

root@apukeller:/etc/config# ping www.heise.de
PING www.heise.de (2a02:2e0:3fe:1001:7777:772e:2:85): 56 data bytes
64 bytes from 2a02:2e0:3fe:1001:7777:772e:2:85: seq=0 ttl=56 time=10.535 ms
64 bytes from 2a02:2e0:3fe:1001:7777:772e:2:85: seq=1 ttl=56 time=11.466 ms

Here is a tcpdump for when I try to contact the host via ping which forces a dns query.

10:51:23.704892 lo    In  IP 127.0.0.1.60710 > 127.0.0.1.53: 42672+ A? cname.example.com. (34)
10:51:23.705001 lo    In  IP6 ::1.60710 > ::1.53: 42672+ A? cname.example.com. (34)
10:51:23.705051 lo    In  IP 127.0.0.1.60710 > 127.0.0.1.53: 44114+ AAAA? cname.example.com. (34)
10:51:23.705096 lo    In  IP6 ::1.60710 > ::1.53: 44114+ AAAA? cname.example.com. (34)
10:51:23.705282 mainbridge.62 Out IP6 fd01:4dd0:28d4:7300::10.58728 > fd01:4dd0:28d4:7300::1f.53: 34427+ A? cname.example.com. (34)
10:51:23.705285 mainbridge Out IP6 fd01:4dd0:28d4:7300::10.58728 > fd01:4dd0:28d4:7300::1f.53: 34427+ A? cname.example.com. (34)
10:51:23.705294 eth0  Out IP6 fd01:4dd0:28d4:7300::10.58728 > fd01:4dd0:28d4:7300::1f.53: 34427+ A? cname.example.com. (34)
10:51:23.705495 mainbridge.62 Out IP6 fd01:4dd0:28d4:7300::10.41962 > fd01:4dd0:28d4:7300::1f.53: 6937+ AAAA? cname.example.com. (34)
10:51:23.705499 mainbridge Out IP6 fd01:4dd0:28d4:7300::10.41962 > fd01:4dd0:28d4:7300::1f.53: 6937+ AAAA? cname.example.com. (34)
10:51:23.705505 eth0  Out IP6 fd01:4dd0:28d4:7300::10.41962 > fd01:4dd0:28d4:7300::1f.53: 6937+ AAAA? cname.example.com. (34)
10:51:23.705723 eth0  In  IP6 fd01:4dd0:28d4:7300::1f.53 > fd01:4dd0:28d4:7300::10.58728: 34427 1/0/0 CNAME hostA.example.com. (67)
10:51:23.705731 mainbridge In  IP6 fd01:4dd0:28d4:7300::1f.53 > fd01:4dd0:28d4:7300::10.58728: 34427 1/0/0 CNAME hostA.example.com. (67)
10:51:23.705734 mainbridge.62 In  IP6 fd01:4dd0:28d4:7300::1f.53 > fd01:4dd0:28d4:7300::10.58728: 34427 1/0/0 CNAME hostA.example.com. (67)
10:51:23.705903 eth0  In  IP6 fd01:4dd0:28d4:7300::1f.53 > fd01:4dd0:28d4:7300::10.41962: 6937 2/0/0 CNAME hostA.example.com., AAAA fd01:4dd0:28d4:5000::13 (95)
10:51:23.705908 mainbridge In  IP6 fd01:4dd0:28d4:7300::1f.53 > fd01:4dd0:28d4:7300::10.41962: 6937 2/0/0 CNAME hostA.example.com., AAAA fd01:4dd0:28d4:5000::13 (95)
10:51:23.705910 mainbridge.62 In  IP6 fd01:4dd0:28d4:7300::1f.53 > fd01:4dd0:28d4:7300::10.41962: 6937 2/0/0 CNAME hostA.example.com., AAAA fd01:4dd0:28d4:5000::13 (95)
10:51:23.706017 lo    In  IP 127.0.0.1.53 > 127.0.0.1.60710: 42672 1/0/0 CNAME hostA.example.com. (67)
10:51:23.706111 lo    In  IP6 ::1.53 > ::1.60710: 42672 1/0/0 CNAME hostA.example.com. (67)
10:51:23.706529 lo    In  IP 127.0.0.1.53 > 127.0.0.1.60710: 44114 0/0/0 (34)
10:51:23.706612 lo    In  IP6 ::1.53 > ::1.60710: 44114 0/0/0 (34)

As a result I cannot fetch a new letesencrypt cert, which is unfortunate of course.