Django ManyToManyField not showing in admin - django

Question

As this questions says, I am having trouble displaying a ManyToManyField in the django admin page.
The m2m field that I'm having trouble displaying is comics in the Gig model.
Here is the code for my project:
#models.py file
class Host(models.Model):
user = models.OneToOneField(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name='host')
name = models.CharField("Venue Name", max_length=200)
slug = models.SlugField(allow_unicode=True, blank=True, null=True)
description = models.TextField("Brief Venue Description - [50 Characters Max]", max_length=50, blank=True)
profile_pic = models.ImageField("Profile Picture", upload_to='host/profile_pics',blank=True)
class Gig(models.Model):
host = models.ForeignKey(Host, on_delete=models.CASCADE, blank=True, related_name='host_gigs')
title = models.CharField("Gig Title",max_length=50, null=True)
date_time = models.DateTimeField("Date/Time of Gig", null=True, blank=True)
description = models.TextField("Describe this gig", max_length=150, blank=True)
instructions = models.CharField('Instructions for accepted comics', max_length=200, blank=True, null=True)
comics = models.ManyToManyField("comic.Comic", through='comic.ComicGig',related_name='gig_comics', default=" ")
#in separate app
#models.py
class Comic(models.Model):
user = models.OneToOneField(settings.AUTH_USER_MODEL,on_delete=models.CASCADE, related_name='comic')
dob = models.DateField("Date of Birth", null=True, blank=True)
mobile = PhoneNumberField(null=True, blank=True)
slug = models.SlugField(allow_unicode=True, blank=True, null=True)
class ComicGig(models.Model):
thegig = models.ForeignKey('host.Gig', on_delete=models.CASCADE, default="", related_name='comic_gig')
comic = models.ForeignKey(Comic, on_delete=models.CASCADE, default="")
approved_comic = models.BooleanField(default=False, null=True)
def approve(self):
self.approved_comic = True
self.save()
Here is my Host admin.py file:
class AuthorAdmin(admin.ModelAdmin):
list_display = ('host', 'title',)
filter_horizontal = ('comics',)
def formfield_for_manytomany(self, db_field, request, **kwargs):
if db_field.name == "comics":
kwargs["queryset"] = Gig.objects.filter(comic_gig__approved_comic=True)
return super().formfield_for_manytomany(db_field, request, **kwargs)
admin.site.register(Host)
admin.site.register(Gig, AuthorAdmin)
Here is a picture of my Host model in the admin
Here is a picture of my ComicGig model in the admin