M6e Nano + Arduino Uno Wifi + UHF RFID Antenna (RP-TNC) Reading worse than internal M6e Nano Antenna

Hello,

I am trying to create an RFID Inventory solution where UHF Gen2 tags are attached to a box of products and Simultaneous RFID Reader reads those tags and Arduino Uno Wifi sends it down the chain.

I purchased the recommended UHF RFID Antenna from Sparkfun (RP-TNC) to increase the reading range but I am getting worse of a reading with the external Antenna than with the internal M6e Nano Antenna.

Reading Strength is set to 27db (max), I soldered all of the jumpers as instructed.

I am using these tags (https://www.amazon.com/AZ9662-ISO18000- … BKMYM?th=1)

Arduino is powered by an external power supply (https://www.amazon.com/gp/product/B018O … UTF8&psc=1)

Can someone please point me in the right direction to get a better reading range with the external Antenna?

Thank you!

Are you also using the Interface Cable RP-SMA to U.FL (WRL-00662)?

Yes I am, and also this one too

https://www.sparkfun.com/products/14132

I narrowed it down to the Simultaneous RFID Reader (M6e Nano) after hooking up the antenna to another reader successfully.

Can you please help me solve the M6e Nano issue? How can I troubleshoot it further?