I found some samples of Fuji X-T4 raws that LibRaw seems to have problems handling.
There seems to be a few things going wrong with this one. The version that parse_fuji_compressed_header() finds is version 0 which is not supported as the check is for version != 1. This image does appear to be compressed though (half the file size of a normal X-T4). Not sure if LibRaw will support a version 0 compression algorithm but just something I noticed, also all the other conditions are satisfied as true for the compression check.
As well something is off with the sizes (height reporting as 1004).
raw_height = 4182
raw_width = 6384
height = 1004
width = 6276
cleft = 6
ctop = 13
cwidth = 6240
cheight = 4160
Not sure if you guys have this resolved in another branch or area but if there is a place to provide samples I can share the ones I found.