Issue filtering on labels doesn't always work

Summary

Filtering issues on certain labels doesn't work. For some labels, the correct result is returned, and for others an empty result is returned.

It seems like it could have something to do with project- vs group-level labels. Trying to filter on group-level labels seem to work, but project-level labels don't work.

Steps to reproduce

1. Filter on an affected label on the issues page for a project or the group.

Example Project

What is the current bug behavior?

No matching issues are returned.

What is the expected correct behavior?

All the issues that have the corresponding label should be returned.

Relevant logs and/or screenshots

There are definitely issues with this specific label:

But filtering specifically on it yields no results:

Output of checks

Results of GitLab environment info

Expand for output related to GitLab environment info

System information
System:		Ubuntu 18.04
Proxy:		no
Current User:	git
Using RVM:	no
Ruby Version:	2.7.2p137
Gem Version:	3.1.4
Bundler Version:2.1.4
Rake Version:	13.0.3
Redis Version:	6.0.10
Git Version:	2.31.1
Sidekiq Version:5.2.9
Go Version:	unknown

GitLab information
Version:	13.11.1-ee
Revision:	557bbaae5b1
Directory:	/opt/gitlab/embedded/service/gitlab-rails
DB Adapter:	PostgreSQL
DB Version:	12.6
URL:		<>
HTTP Clone URL:	https://<>/some-group/some-project.git
SSH Clone URL:	git@<>:some-group/some-project.git
Elasticsearch:	no
Geo:		no
Using LDAP:	yes
Using Omniauth:	yes
Omniauth Providers: 

GitLab Shell
Version:	13.17.0
Repository storage paths:
- default: 	/var/opt/gitlab/git-data/repositories
GitLab Shell path:		/opt/gitlab/embedded/service/gitlab-shell
Git:		/opt/gitlab/embedded/bin/git

Results of GitLab application Check

Expand for output related to the GitLab application check

Checking GitLab subtasks ...
Checking GitLab Shell ...
GitLab Shell: ... GitLab Shell version >= 13.17.0 ? ... OK (13.17.0)
Running /opt/gitlab/embedded/service/gitlab-shell/bin/check
Internal API available: OK
Redis available via internal API: OK
gitlab-shell self-check successful
Checking GitLab Shell ... Finished
Checking Gitaly ...
Gitaly: ... default ... OK
Checking Gitaly ... Finished
Checking Sidekiq ...
Sidekiq: ... Running? ... yes
Number of Sidekiq processes (cluster/worker) ... 1/1
Checking Sidekiq ... Finished
Checking Incoming Email ...
Incoming Email: ... Reply by email is disabled in config/gitlab.yml
Checking Incoming Email ... Finished
Checking LDAP ...
LDAP: ... Server: ldapmain
LDAP authentication... Anonymous. No bind_dn or password configured
LDAP users with access to your GitLab server (only showing the first 100 results)
User output sanitized. Found 54 users of 100 limit.
Checking LDAP ... Finished
Checking GitLab App ...
Git configured correctly? ... yes
Database config exists? ... yes
All migrations up? ... yes
Database contains orphaned GroupMembers? ... no
GitLab config exists? ... yes
GitLab config up to date? ... yes
Log directory writable? ... yes
Tmp directory writable? ... yes
Uploads directory exists? ... yes
Uploads directory has correct permissions? ... yes
Uploads directory tmp has correct permissions? ... yes
Init script exists? ... skipped (omnibus-gitlab has no init script)
Init script up-to-date? ... skipped (omnibus-gitlab has no init script)
Projects have namespace: ...
4/1 ... yes
4/2 ... yes
5/3 ... yes
5/4 ... yes
4/5 ... yes
6/6 ... yes
4/7 ... yes
6/8 ... yes
6/9 ... yes
4/10 ... yes
4/11 ... yes
4/12 ... yes
6/13 ... yes
4/14 ... yes
5/15 ... yes
4/16 ... yes
6/17 ... yes
4/18 ... yes
4/19 ... yes
4/20 ... yes
4/21 ... yes
66/22 ... yes
4/23 ... yes
6/24 ... yes
4/25 ... yes
4/26 ... yes
8/27 ... yes
10/28 ... yes
16/29 ... yes
18/30 ... yes
22/31 ... yes
23/32 ... yes
24/33 ... yes
29/34 ... yes
30/35 ... yes
34/36 ... yes
35/37 ... yes
37/38 ... yes
40/39 ... yes
41/40 ... yes
43/41 ... yes
45/42 ... yes
50/43 ... yes
45/44 ... yes
7/45 ... yes
4/46 ... yes
4/47 ... yes
45/51 ... yes
4/52 ... yes
45/53 ... yes
39/54 ... yes
45/55 ... yes
45/56 ... yes
41/57 ... yes
4/58 ... yes
54/59 ... yes
15/60 ... yes
24/61 ... yes
23/62 ... yes
56/63 ... yes
4/64 ... yes
4/65 ... yes
4/66 ... yes
4/67 ... yes
4/68 ... yes
51/71 ... yes
65/72 ... yes
61/73 ... yes
59/74 ... yes
4/75 ... yes
62/76 ... yes
4/77 ... yes
24/78 ... yes
4/79 ... yes
45/80 ... yes
56/81 ... yes
4/82 ... yes
66/83 ... yes
18/84 ... yes
41/85 ... yes
45/87 ... yes
4/88 ... yes
4/89 ... yes
4/90 ... yes
35/91 ... yes
18/92 ... yes
50/93 ... yes
41/94 ... yes
45/95 ... yes
5/96 ... yes
45/97 ... yes
68/98 ... yes
37/99 ... yes
4/100 ... yes
41/101 ... yes
16/102 ... yes
70/103 ... yes
45/104 ... yes
71/105 ... yes
69/106 ... yes
35/107 ... yes
66/108 ... yes
18/109 ... yes
8/110 ... yes
41/111 ... yes
62/112 ... yes
69/113 ... yes
62/114 ... yes
70/115 ... yes
45/116 ... yes
70/117 ... yes
72/118 ... yes
41/119 ... yes
45/120 ... yes
74/121 ... yes
4/122 ... yes
4/123 ... yes
34/124 ... yes
4/125 ... yes
41/126 ... yes
69/127 ... yes
41/128 ... yes
68/129 ... yes
65/130 ... yes
75/131 ... yes
18/132 ... yes
69/133 ... yes
50/134 ... yes
69/135 ... yes
27/136 ... yes
69/137 ... yes
50/139 ... yes
24/140 ... yes
4/141 ... yes
18/142 ... yes
8/143 ... yes
45/144 ... yes
30/145 ... yes
77/146 ... yes
50/147 ... yes
61/148 ... yes
50/149 ... yes
4/150 ... yes
45/151 ... yes
45/152 ... yes
50/153 ... yes
4/154 ... yes
41/155 ... yes
18/156 ... yes
4/157 ... yes
41/158 ... yes
66/159 ... yes
45/160 ... yes
56/161 ... yes
45/162 ... yes
Redis version >= 5.0.0? ... yes
Ruby version >= 2.7.2 ? ... yes (2.7.2)
Git version >= 2.31.0 ? ... yes (2.31.1)
Git user has default SSH configuration? ... yes
Active users: ... 40
Is authorized keys file accessible? ... yes
GitLab configured to store new projects in hashed storage? ... yes
All projects are in hashed storage? ... yes
Elasticsearch version 7.x (6.4 - 6.x deprecated to be removed in 13.8)? ... skipped (elasticsearch is disabled)
Checking GitLab App ... Finished
Checking GitLab subtasks ... Finished

Possible fixes