The 8BitDo Mod Kit for Original SNES/SFC Controller has slightly slimmer shoulder button PCB's compared to original controllers. This can result in missing inputs because the conductive rubber barely touches the PCB in some cases.
If your original controller has trouble registering inputs, you can try to print the SNES shoulder button riser and see if that helps. Start from thinnest and work your way up there.
I'd recommend cleaning or getting completely new conductive rubbers first. It might be enough to fix the issue with our controller.
I fixed my 8BitDo Mod Kitted controller with 0.8 mm riser and 1.0 mm PCB support.
Mix and match and see what works for you.
Printed with these settings:
Layer height: 0.20 mm
Infill: 100%
The author marked this model as their own original creation.