It turns out most users exhibiting these symptoms have used METAL (or) SHARP (or) LARGE tools to remove the CPU shield, and in doing so, they have damaged either or both the two small caps located just outside of the shield area. (see pic below)
The shield needs to be removed carefully using plastic or small tools and the installer needs to start on the other side where there are no nearby components which could be easily damaged.
Resoldering these two caps back in place, or replacing them with a similar SMD 0.1uf 10v 0201 part will solve all your issues from getting stuck at the 'JoyCon' logo. It is recommended to get a professional installer to do the job for you, if you don't have the correct tools to complete your SX Core installation successfully.
That's all today, and remember if you have any technical support issues with our products, please contact our tech staff at tech @ xecuter . com or reach out to our very helpful TX Community of fellow users on our TX Chat Server.