Error when Scan I2C Devices by AnyI2C v1.2.0

I have the following devices.

PR54-11 8-Channel Multiplexer. Dual USB to 8-Port Hardware I2C Converter
MG-811 CO2 Gas Sensor
MQ135 Ozone Gas Sensor
CCS811 Air Quality Sensor
SHT25 Humidity and Temperature Sensor

And I test whether each device is normal using the Scan I2C Devices function of the AnyI2C program.

However, there are some problems in which devices are sometimes found but not in some cases.

Is there any solution for this?

HI,
can you share a picture of your setup.
@ryan1 do you happen to know what could cause this

AnyI2C was created by an engineer that is no-longer with our company. The I2C Scan features were not completed in AnyI2C. Please use Alpha Station for I2C Bus Scanning operations (https://ncd.io/alpha). Other operations in AnyI2C should work, but I am not sure about the port selection routines. Our latest examples are in Alpha Station, though it does not have the range of support of AnyI2C at this time. Please let me know if this helps.
Ryan