When trying to move files in subdirectories, tcc16/17 only move the one from the first dir and then stop if the directory contains multiple files. Try this batch to reproduce, tcc16/17 only move "x.txt" while tcc15 and tcc-le move all three .txt files as requested
mkdir bug\1 bug\2
cd bug\1
touch /c a\x.txt a\x.bat b\y.txt b\y.bat c\z.txt c\z.bat
move *.txt ..\2 /s
cd ..\..
mkdir bug\1 bug\2
cd bug\1
touch /c a\x.txt a\x.bat b\y.txt b\y.bat c\z.txt c\z.bat
move *.txt ..\2 /s
cd ..\..