Power supply problem of DFR0576

From the datasheet, the power supply for this Multiplexer is from 3.3V to 5V.

But when I connect the 3.3V, it doesn’t work. When I connect 5V, it can work for 1 piece only, another piece doesn’t work. But half day later, when I test it again, all of them cannot work under 5V, it only works when I connect to the power supply with voltage above 5.7V.

Could you help to check the reason? Below is the link of the product, thanks!

DFR0576 DFRobot | Development Boards, Kits, Programmers | DigiKey

Checking one this. Will let you know when I have the answer.

A schematic for the board can be found here, and the datasheet for the target IC here.

Increasing the supply voltage above about 5V would cause the on-board pull up voltage to fall below the valid logic-high range; the board would not be expected to function under these conditions.

Some kind of error in the connected circuits is the most likely explanation. I would suggest measuring the waveforms directly using an oscilloscope as a step toward understanding the problem.