Attachments have changed greatly in Season 13 and need to be manually redone on the site. This will take quite some time, so apologies if this section isn't helpful right now.
Attachment Details
Merc Foregrip
Underbarrel
Added in version 1.0.15.0 1.0.15.17
Controls recoil and maintains stability when hipfiring. Suitable for fast-paced combat.