A slight confusion in using tense.
Hello,
I got a sentence, let me write it-
"The old man who is sitting in that room lived here for more than a month but he has never created any problem."
Is this sentence correct? "Lived" is all right or "had been" should be used? And I think the "has" should be replaced with past simple or past perfect. Am I right?
Thank you!

Question

A slight confusion in using tense.
Hello,
I got a sentence, let me write it-
"The old man who is sitting in that room lived here for more than a month but he has never created any problem."
Is this sentence correct?  "Lived" is all right or "had been" should be used? And I think the "has" should be replaced with past simple or past perfect. Am I right?
Thank you!

Answer

This is tricky because I'm not sure of your time sequence.

He is sitting -> happening right now.

But: is he still living there now or not?

If so, In addition to Michael's correct answer, you could say "has been living" it the first part of the sentence and keep "has never created" at the end. Both actions that started in the past and are continuing.

If he not living there now (but did in the past), you want "lived" and then "never created." Both completed past actions.

Answer

If you change it to "has lived", then it indicates that the man is still living in the same place.  It then makes sense.