Perché viene visualizzato solo un tag?

I have put 4 tags but it only shows 1 of them beneth the topic title.

Is this normal behaviour?

Duplicated words will not appear in tags unless you enable the “show duplicate words” setting.

It is a bit redundant to have the tags in the title as well.

It is. It is not intuitively one expect however, since it is an exception.

Thank you for confirming!