product tag adds %20

When I use product tags, if there is a gap it is filled with %20
I have a product tag that is Pixma MG7750
When I click it, in the url it says
/index.php?route=product/search&tag=Pixma%20MG7750. Result..............there is no search result.
How can I fix this.
thank you

Product tags should be comma seperated (if i am correct) and %20 is the code for a space
So enter either PixmaMG7750 or Pixma,MG7750