Hello Martin,

I have never tried WSPR-X. The manual states:

>>> The recommended WSPR-15 sub-band is a 25 Hz slice just above the 
200-Hz WSPR-2 sub-band, i.e., 1600-1625 Hz above the standard dial 
frequency on each band. This will be handled automatically if you 
set up WSPR-X in the normal way. <<<

I do not see any signal in that range.
Are you sure someone is actually using this mode at the moment?

73,
Roelof, PAoRDT