2015 Polo Bluemotion Horn sounding

[Gutrit]

Good day All,

I was wondering if someone can assist with some info, I had the SO's 2015 Polo Bluemotion in for the EGR, DPF and Cat removal with this it was slightly tuned as well.
Since she got it back the horn would randomly sound when starting the vehicle, sometimes. Does anyone have an idea what it could be.
I had it back at the garage who assisted with the work and they said there is nothing wrong with the coding they done.

Perhaps someone have experienced this before after software modifications?