Since I just went through this myself, I thought I'd offer up some hints...
First off, OP's dig query is reading information from their own DNS server, and not from the glue records. To get the glue records, you first need to know the nameservers for your domain's TLD. We'll work with OP's .net domain as an example:
# dig +short NS net.
l.gtld-servers.net.
f.gtld-servers.net.
i.gtld-servers.net.
m.gtld-servers.net.
b.gtld-servers.net.
a.gtld-servers.net.
g.gtld-servers.net.
e.gtld-servers.net.
d.gtld-servers.net.
c.gtld-servers.net.
k.gtld-servers.net.
h.gtld-servers.net.
j.gtld-servers.net.
Pick any one of the servers from the list, it doesn't matter which. Now we can read the glue record directly from the TLD:
# dig +norec NS ns2.sdsitehosting.net @d.gtld-servers.net
; <<>> DiG 9.8.4-rpz2+rl005.12-P1 <<>> +norec NS ns2.sdsitehosting.net @d.gtld-servers.net
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 27100
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 2, ADDITIONAL: 4
;; QUESTION SECTION:
;ns2.sdsitehosting.net. IN NS
;; AUTHORITY SECTION:
sdsitehosting.net. 172800 IN NS puck.nether.net.
sdsitehosting.net. 172800 IN NS ns2.sdsitehosting.net.
;; ADDITIONAL SECTION:
puck.nether.net. 172800 IN A 204.42.254.5
puck.nether.net. 172800 IN AAAA 2001:418:3f4::5
ns2.sdsitehosting.net. 172800 IN A 173.230.157.122
ns2.sdsitehosting.net. 172800 IN AAAA 2600:3c01::f03c:91ff:fe96:bbec
;; Query time: 22 msec
;; SERVER: 192.31.80.30#53(192.31.80.30)
;; WHEN: Thu Jun 1 09:42:51 2017
;; MSG SIZE rcvd: 167
The information you are looking for is in the Additional section, and this shows that OP has been able to successfully add IPv6 glue records since their original post.
The important thing here is that YOU cannot add glue records simply by adding AAAA records to your domain's DNS. This is something you need to handle through your domain registrar, and not all of them are capable of working with IPv6. For example, my domains are through NameCheap -- two weeks ago I asked them to add glue records for two of my domains. The .us domain was updated within a few hours, but I'm still waiting for the .net domain to be updated. What you want to look for at your registrar's web site is the ability to add nameservers to your domain. This is not the same as your registrar managing DNS records, this is something that should be directly within management of your domain. In the case of NameCheap there is a tab for Advanced DNS, and under that it allows me to add new IPv4 nameservers by entering the domain (such as ns1.example.com) and IP address (the actual IP of my own DNS servers). Some registrars may allow you to directly enter IPv6 records here, but NameCheap required me to submit a trouble ticket. The nameservers you enter in this location are the same entries you will see when you perform a 'whois' on your domain. Additionally, you can add nameservers from other domains. In my case I had nameserver entries from both my .net and .us domain entered, so when HE tried checking my .net domain for IPv6 glue records, it successfully found the .us IPv6 glue records allowing me to pass the Sage test.