TCA9548A - Adafruit vs. generic clones

I bought a Adafruit branded TCA9548A I2C mux as well as some generic TCA9548A development boards from Amazon (In fact they look just like what is pictured on this video:

I have the adafruit one working just fine with an Arduino Pro Micro and three128x32 I2C OLEDs on attached to the mux. I have pull up resistors for the signal lines on the OLEDs and it all works great. In fact my schematic is exactly as shown in the above video.

If I substitute the "generic" mux dev boardthe screens never light up. I can see the mux address with the I2Cscanner, it is at least partially working

Has anybody else come across anything similar to this?

In fact my schematic is exactly as shown in the above video.

Do you expect us to see a 10 min. video to find the schematics you write about?

If I substitute the "generic" mux dev boardthe screens never light up. I can see the mux address with the I2Cscanner, it is at least partially working

My guess: you got a broken Chinese fake board. As the scanner reports an address you might be lucky and got a working chip but that doesn't say the board is correctly wired.

I have one golden rule: Never buy boards you don't get schematics for (or at least a serious documentation). Chinese boards might be cheap but often you have to buy a dozen of them to get one that works. So in the end you go better with a serious vendor.