Create a tag set with 20+ characters and relationships each.
Create a challenge using that set
Sign up for the challenge
on the /collections/$COLLECTION/signups/new page, click on "Show Characters" then "Show Relationships"
If "lucky", the cache kicks in and either "Show Characters" will show the relationships, or vice versa.
Even if the correct type of tags shows, the tags in it may be wrong (especially if wrangling, not edits to the tag set, has changed the tags).
There is also a fandoms version of this page, e.g. http://archiveofourown.org/tag_sets/show_options?restriction=10986&tag_type=fandom
Make sure the Show Characters/Relationships/Fandoms pages show the right kind of tags.
After visiting the Show Characters/Relationships/Fandoms page, try modifying the tags in the tag set, and making sure the page updates.
After visiting the Show Characters/Relationships/Fandoms page, as a wrangler, try editing the diacritics or suffix of a tag in the tag set and checking if the page updates.
Tagged for 0.9.257 not because this is urgent, but because it also conveniently fixes which is urgent.
Created a tag set with 21 characters and 21 relationships: https://test.archiveofourown.org/tag_sets/528
Created a minimal collection. Created a gift exchange on top of it, open for sign-ups, using the above tag set.
Checked the sign up form, followed "List 21 Characters" and "List 21 Relationships":
Signed up successfully (requested 1 of each type, offered 1 of each type).
( looks good.)
Edited the tag set to add 21 fandoms, 1 character, and 1 relationship.
Checked the sign up form, followed "List 22 Characters" and "List 22 Relationships". The new character/relaionship showed up.
Followed "List 21 Fandoms". Fandoms are displayed.
Now for some tag wrangling:
Edited https://test.archiveofourown.org/tags/Hermione%20Granger/edit to "Hermione GrangeR".
Edited https://test.archiveofourown.org/tags/Ayanami%20Rei*s*Souryuu%20Asuka%20Langley/edit to "Ayanami Rei/Souryuu AsuKa Langley".
Edited https://test.archiveofourown.org/tags/Genesis%20(Band)/edit to "GeneSIS (Band)".
The Show Characters/Relationships/Fandoms pages were updated and displayed the latest capitalization of the edited tags.
The tag set page did not update (e.g. https://test.archiveofourown.org/tag_sets/528). I think this is AO3-3757.
Edited the tags back to how they were.
1) Created a tag set with more than 20 of each kind of tag
2) Created a gift exchange using that tag set
3) Went to the signup form and clicked on each "List [X] [Tag Type]" button
All tag types gave me a full list containing the correct tags
4) Edited the tag set to remove a relationship and add a character, then reloaded the signup form and went to the Character and Relationship lists
Both lists reflected the updates
5) Edited the William Adama character tag to make it William Adáma
Change shows on "List 23 Characters" page. As noted by redsummernight above, change doesn't appear in tag set until the tag set is edited.