Keyboard key to select multiple file items.

I am new to Mac and am having some trouble selecting multiple items in a row. What I have read states to use: click - shift - click which would select all items in a row between the two files. And to select multiple file items individually use: click - command - click etc.

However when I use shift, it functions the same as using the command option; selecting multiple individual files rather than files in a row.

Other users seem to have the opposite problem. 🙂

Thanks for any help!