Forza Horizon 4 Horn Bug not unlocking

I got the horn called Wah Wah Wah Wahh got it from wheelspin and checked the horns and I looked it’s still locked for some reasons so I found this bug on Forza Horizon 4

see
https://forums.forza.net/turn10_postsm1027153findlastpost_Bug-draw-Horn-Forza-Horizon-4--Fortune-Island.aspx#post1040579