You are right. The performance of West Indies players in Test format is very poor. Although they can play well in T20 format, we rarely see good performances from West Indies players in Test format. West Indies players have very little patience. No West Indies player can survive at the crease for long. And this is why we don't see West Indies players performing well in the Test format against the big teams.
West Indies players are not in good form now. This renowned team could not qualify for the last ODI World Cup. West Indies' poor performance started after several players in the squad retired simultaneously. I would say West Indies players need to be more patient and hard working. If not, we will not see good performance from this team in the future.
Most of the West Indies players who have been given opportunities are new players and inexperienced players. We go back to the West Indies team of yesteryear when Chris Gayle, Kieron Pollard, Shivnarayaan Chandrapaul were regulars but their Test team was very strong as in other formats. The performance of the current players of the West Indies team is not promising. But I remember one West Indies batsman I watched playing was Brian Lara who single-handedly scored 400 runs in an innings which is still a world record in Test history.West Indies need a Brian Lara like this now so that they can play well and win the Test series as well.