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
MX9 - Strike Foregrip
Underbarrel
Added in version 1.0.26.0 1.0.26.20
Provides vertical recoil control and increased accuracy when ADS'ing, but mobility is slightly reduced.