I am confused about the word furthermore in the middle of the sentence. Can I use it like this?
However currently both systems are functioning, furthermore, for different issues.
It is put in the middle of the sentence without any additional verb. Is it right? And does it make sense?
Also are the words furthermore and moreover interchangeable?
Although furthermore can be used as you do in your sentence, it usually introduces a new clause, appearing at the head of the clause. You will find moreover far more often in your pattern.
On a separate issue, the phrase functioning for different issues while grammatical, is not quite idiomatic. The usual phrase is addressing different issues.
The word both is wrong (unless there's a third issue in the context).
both systems are addressing different issues.
You'd want to say each;
... each system is addressing a different issue.
And you don't want to combine However and furthermore in the same clause.
