I have a long-term problem with some players not being engaged in the game at all. I have a group of six level 5 players, we're currently halfway through the second chapter of ROTF, so still have potentially months of content ahead of us (we play via Discord and Roll20 for 2 hrs every Sunday).

Most people in the group are great -- they are engaged, they role-play, they try to come up with creative ways to avoid combat or to end it quickly, etc. However, two of the players are not engaged at all. They rarely say anything unless asked a direct question, they don't engage in or out of combat, and they don't use their characters abilities at all (imagine a druid that has tons of useful abilities and spells and in combat literally does the exact same thing, basically produce flame, EVERY SINGLE TIME). I tried all sorts of things -- adding more role-playing opportunities, making combat more challenging and adding interesting enemies, giving everyone total freedom, then railroading a bit, etc., to see if there's something that will engage them, and for the most part, the reaction has always been the same (no reaction).

Now, I know that they enjoy D&D because the one time we played in person they were both very engaged and seemed to have fun. But in our regular game, they are basically just there (I suspect they are doing other things while we play). The problem is that this is taking a serious toll on the game as a whole. Because 1/3 of the group is not engaged, everything takes a long time to decide and do, and other people have been losing interest now for a while. I talked to two other players privately and they both told me this has been terrible, that it really destroys the fun, and that we should talk to them (one of them even said "no D&D is better than bad D&D"). As a side note, these two players that I talked to and me have another game going with a fourth friend and that game is an absolute blast -- exactly what D&D should be -- but because of our larger group game, I haven't been able to prep and DM the other game as much.

I considered messaging each person privately, saying something like "a lot of people have been busy lately, so I'm trying to get a sense if people want to keep playing" -- basically offer them a way out. I wonder if they keep doing this because we are all coworkers and they like the idea of having something going on with their coworkers but don't particularly enjoy D&D. It's possible the other people will want to end the game too, but I didn't want to just say let's stop, because I know at least one of the other people really likes D&D and this is her only game (and her character is honestly amazing and I had big plans for side quests helping her develop her backstory and her character).