SERVFAIL response from 1.1.1.1

I get a SERVFAIL from 1.1.1.1 when trying to resolve git.uzer.one:

dig @1.1.1.1 git.uzer.one AAAA

; <<>> DiG 9.11.5-P1-1ubuntu2.6-Ubuntu <<>> @1.1.1.1 git.uzer.one AAAA
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 29631
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

if I query the nameserver directly:

dig @p.ns.arvancdn.com git.uzer.one AAAA +dnssec

; <<>> DiG 9.11.5-P1-1ubuntu2.6-Ubuntu <<>> @p.ns.arvancdn.com git.uzer.one AAAA +dnssec
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 38137
;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 4, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags: do; udp: 4096
; COOKIE: fb514c71c08742af (echoed)
;; QUESTION SECTION:
;git.uzer.one.			IN	AAAA

;; AUTHORITY SECTION:
uzer.one.		3600	IN	SOA	p.ns.arvancdn.com. hostmaster.arvancloud.com. 1585509282 86400 7200 604800 7200
uzer.one.		3600	IN	RRSIG	SOA 5 2 3600 20200406204656 20200329174656 62616 uzer.one. JVIrLjN3RwECytgfxVBlD9FFZXK4wl1NDj4cJxc+H+8hIa+AqccX2/em BZFaaQ59N/wiOaZfy+R4bSHKvPG3W8ucZyrRHwXs8jfTd8ynHtp29+ti c0HApBA2TpA/beVn6Kob4lfiMPtG3ffxCtM60+Nq8kf/SwbzEk+RGPtc OnU=
git.uzer.one.		7200	IN	NSEC	\000.git.uzer.one. A CNAME PTR MX TXT SRV RRSIG NSEC TLSA CAA
git.uzer.one.		7200	IN	RRSIG	NSEC 5 3 7200 20200406204656 20200329174656 62616 uzer.one. SBCqz7KCRkqKXIjzlOk/pncRG/94e1awZ7Ci0PcvIcII5l3jun22qeN9 ZtQzjWw60jIR1AUFp4cG35mIqbfJ4nfRmE7gc1PaDfXLRBUk2rFp5d6W G1piLGBPVSThcJ43rzGewkOBxQz4stmb8gq+ASsUJXVWUCxqGNfwVo9l sBw=

it looks like a problem with NSEC nonexistent proof. but I can’t figure out what the problem is.
4.2.2.4 works fine and 8.8.8.8 seems to also have problem

Might be edns related, although I can’t say for sure.

https://ednscomp.isc.org/ednscomp/b551cbdf62

thanks for your quick response
It’s not likely, failed tests are those with edns version set to 1, which is not the case here.