help request: unable to merge UTF-16-LE "text" file

Greetings,

I've been struggling to merge branches because of a UTF-16-LE (with BOM?) file.

Windows 11 / git version 2.35.3.windows.1

The problem file is a .sln file (Visual Studio "solution"). Edited in both branches. It is a "text" file, but is encoded as such:

FacilityMaster.sln: Unicode text, UTF-16, little-endian text, with CRLF line terminators

I have tried several "working-tree-encoding" settings in .gitattributes in my local working directory, to no avail yet:

*.sln working-tree-encoding=UTF-16-LE eol=CRLF, results in: error: failed to encode 'FacilityMaster.sln' from UTF-16-LE to UTF-8 warning: Cannot merge binary files: FacilityMaster.sln (HEAD vs. master)

*.sln working-tree-encoding=UTF-16 eol=CRLF, results in: warning: Cannot merge binary files: FacilityMaster.sln (HEAD vs. master)

*.sln working-tree-encoding=UTF-16-LE-BOM eol=CRLF error: failed to encode 'FacilityMaster.sln' from UTF-16-LE-BOM to UTF-8 warning: Cannot merge binary files: FacilityMaster.sln (HEAD vs. master)

Hoping for some suggestions. I've also tried to save the file as UTF-8 in both branches, commit, then merge, but still that did not work. I just want to merge it like a normal source code file.

Thank you,

Kevin Long