subversion commit adding more files than what is expected by "svn merge"

subversion commit adding more files than what is expected by "svn merge"

note: my steps are different than This Stack Overflow Question
1. svn merge -c 261588 https://svn.repo
2. svn commit -m 'message...' (Committed revision 261598.)
and notice that instead of the ONE file , 20 other files are also submitted
so i revert :
svn merge -c -261598 https://svn.repo
svn commit -m 'reverted 261598'
now if i try to commit on a fresh working copy of the repo, i STILL get
the SAME issue of submitting more files than what i expect. How can i
merge this ONE file and not all these others.