MIDI Passthrough via MOSFET

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Hi Folks,

Hitting a snag with a project. I'm trying to control passthrough of MIDI messages using a MOSFET, while still allowing MIDI input and output from a Teensy 4.0. I've successfully controlled a MIDI passthrough by sending the data line through a MOSFET controlled by an arduino uno. However, when I add the ability to output MIDI from the teensy, I get MIDI messages going round and round. It seems like messages from the Teensy output are making their way through the MOSFET in the opposite direction. Any thoughts on how I can get this working? Here's the schematic that I'm working off of now:
 

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Considering the tx line is in no way connected to the rx line in your schematic you may have accidentally bridged the pins when you soldered your header on.
 
Thanks for the speedy response. Right now this is built on a breadboard, so no soldering in the setup yet.

You're post made me take a second look at the schematic and I don't believe I drew it correctly. The tx should be connected to pin 3 on the MIDI output, not pin 2.

Previously, any time a message came into the system and the MOSFET was closed, I would get a round and round loop of the MIDI message. I just powered it up and experienced that. But after I reset the device, I no longer get that issue, and it seems to be working as expected... which is weird.
 
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