[Weird artifacts when working with PSD files with embedded documents]

Hello, everyone.

I updated Affinity Photo to its 1.9 version yesterday.

I need to work on some mockups, but when I open the PSD I'm going to use, I see these weird shapes – but only on the layer with the embedded document. I'm not sure if this is a software issue, or if it's a problem with my graphics card (this had never happened before), but I thought maybe I could get some guidance/assistance here.

Attached you'll find an screenshot of the issue.

Thanks for your help.