UFF Import X-Axis Unit

Hello, I am trialing FlexPro and working with UFF58 files. I have tried several files and for some reason the X-axis unit is not being detected.

When I import the data and plot it everything plots correctly and the sample frequency is correct. The only thing I have to do is specify the X-Unit.

Is there something I am missing or is this the intended behavior. Here is the header of my file.

    -1
    58
REF 1: SD-VXI (0001.005)
NONE
04-Jan-23 05:23:53
NONE
NONE
    1         0    0         0 NONE               0   1 NONE               0   0
         2    131072         1 -4.09600E+00  4.00000E-04            0
        17    0    0    0 Time                 s                
        21    0    0    0 NONE                 mV                  
         0    0    0    0 NONE                 NONE                
         0    0    0    0 NONE                 NONE