x2sys_solve question

Hi
I have 9tracks Ti.dat ( longitude|latitude|free air anomaly ) -> lon | lat | faa
I also have a table of weight: weights.txt -> track | weight

export x2sys_home ...
gmt x2sys_init LLA -Dlla -Edat -V -Gd -Ndk -Nsk -Rd -Wd0.8
gmt x2sys_cross -TLLA *.dat -V1> cross.out
gmt x2sys_list -TLLA cross.out -V -Cfaa -Fncw -Wweights.txt > list.out
gmt x2sys_solve -TLLA list.out -V -Cfaa -Ec -W > solve.out

The problem appears in gmtx2sys_solve, because I want to use the column weights of crossovers that I got in x2sys_list with -Fncw -Wweights.txt but x2sys_solve gives the same solution as if they were all weights 1.
I was looking for examples of x2sys_solve using -W but I couldn't find any.
My questions would be:
Why does x2sys_solve ignore the weight column (the last one) of list.out ?
Am I misusing the x2sys_solve command?

Hope someone can help me
Have a great day
[tracks.zip](https://github.com/GenericMappingTools/gmt/files/7974178/tracks.zip)