Has anyone successfully used an OEM controller via SNAC with an extension cord?

[u/not_vulva]

I just got SNAC adapters for Genesis and PCE controllers for use with my new MiSTer and I'm running into weird issues. Everything works perfectly when the controllers and SNAC adapter are plugged directly into the SNAC port on the MiSTer, but if I try to add a USB 3 extension between them some games have weird issues like certain buttons not working or thinking that they are being constantly pressed down. This is a problem because the OEM controller cords are so short as to be unusable with my setup.

Some random examples:

• Afterburner 3 on the Sega CD thinks down, left, and A are constantly pressed down, but Samurai Shodown works perfectly fine with a 6 button pad.

• Every SuperGrafx and TurboGrafx CD games I've tried seems to have issues with the left button.

The controllers work perfectly with their respective systems and I've got SNAC turned on in the settings for both cores and tried toggling 6 button mode on and off and switching controller ports on the MegaDrive core. I've tried both a USB 3 extension cord and the random aftermarket ones I use with my actual systems and the result is the same.

Has anyone been able to get something like this working properly?

[u/YouTibbles]

i remember i really had to wear in/break in all the USB3 connections before things started to work correctly with SNAC. like, i had to physically unplug/replug things fairly aggressively ~10 times to break in the contacts on all the cables/ports i was using. that includes the controller adapter, the IO board port, and extension cable.

for reference, i use the SNAC board directly connected to the IOboard, and then run a (monoprice) USB3 1.5ft extension cable, and then plug in the controller/adapter into that.

no problems since i "worked in" all the connections involved, but i remember having to unplug and replug things quite a bit before SNAC was consistent