In Voyager season 2, the writers tried to do a serialized story arc with Michael Jonas spying for the Kazon, but it didn't work out as well as they hoped, and I remember Jeri Taylor (IIRC) saying in an interview that their mistake was that they chose to do a plot arc that came from outside the ship instead of a character arc that came from within. Maybe that's why the biggest serialized threads from then on were character-driven -- Seven of Nine's evolution from Borg to human, Paris and Torres's romance, the Doctor's pursuit of personal growth.
Voyager had some of the weirdest character continuity. Right before they were stranded in the DQ, Janeway was engaged to a guy named Mark.
A couple of months later they come to a planet. The leader is a guy named Gath and they spend time together. She seemed charmed by him. Even the other crew members make a comment about it.
Harry Kim was even worse.
Before they were stranded, Harry Kim was supposed to have a girlfriend named Libby (possibly engaged). In the same episode above there was a mention he went on a date with a crewmen. Then later when he meets a female local on the planet they're visiting, he gets very cozy and flirty with her.
Unless Harry was a two timer.
It wouldn't surprise me that arc wasn't as popular. I had a hard time understanding Seska's motives, if she wanted to get to the AQ as fast as possible. It made little sense.
Originally Seska wanted to get home as fast as possible and she didn't think Voyager was ever going to do it Janeway's way.
But she opts to escape and stay with the Kazon who are technology behind Voyager. So she tries to recapture Voyager so the Kazon will get the advanced ship they wanted. She even gets a crew member to spy on them for her.
The problem was, she wasn't going anywhere. That was like a plan to travel in the wrong direction. Why a crewman would want to waste time with a traitor on an alien ship with inferior tech in region that they were leaving behind made little sense.
Voyager had a lot of weird continuity issues, at least from what I've noticed.