Second Sim Icon on Single Sim Variant (Lumia 640 XL)

I flashed the leaked copy of Windows 10 Mobile 10240 onto my Lumia 640 XL not realizing it was a dual sim rom. As I had got a copy of a original windows phone 8 .ffu I thought I'll just flash back to that. However when doing so I am stuck with the second sim icon still. I've even downloaded another single sim .ffu and flashed but phone still thinks it's a dual sim phone. Any ideas?

Thanks