Two possibilities ...
(1.)
The file libstdc++.so.6 you found is actually an Intel shared-object file and not an ARM shared-object file,
The file names are the same, but the files are very different, since compiled for different target computers.
To cross compile in a Windows environment, you need a full set of the ARM shared-object files
to link to. The ARM computer/executables/ can not see an Intel shared-object file,
So you may have some kind of mixed environment problem with your cross-compiler set-up.
(2.)
Could be a Linux permissions/ownership problem.
Likely in one case, the file is owned by 'root', and in the other case, file is owned by a user.
Examine the all files and the executables using ls -al
change the ownership with chown if necessary.
--- Graham
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