I thought fwiep fixed that but as I never tested that or subsequent versions I can't confirm the fix works. Finally, taking a looking at the most recent zip and the fix itself it does something different to what I suggested so I'm guessing not. Sorry to provide such late feedback Frans!
Anyway, I worked around the problem with a setprop command in adb shell:
setprop ro.product.device Y550-L02
This must be done before an install is attempted. It seems values are cached.
FWIW, I used twrp-3.3.0-1-y550 back then.