Dungeons and Dragons is a Team Game of Collaborative Storytelling
I encountered this question on @twitter the other day and wanted to write my response. In my opinion, challenge ratings in ttrpgs have nothing to do with the monster, but rather the play styles of those at the table.

First of all, great follow up as a DM for “talking to the player first”. This increases the flow of communication both ways.
For a refresher, let’s make up 4 play styles regarding combat
- Problem Solvers – clever, prepared and calculated
- Dice Rollers – loves to roll tons of dice and do tons of damage
- Partyfacers – in it for the monologues and catch phrases
- Plotfinders – wants to know “why” combat
With combat, I try to vary the reasons for combat to occur.
- Monsters attack and we must kill them to survive – great for dice rollers!
- Evil cultists attack, but some of them give clues they may be turned – great for partyfacers!
- Predatory creatures in a lair with area effects, traps and environmental hazards – great for problem solvers!
- A portal opens to another realm and out walks a deranged old wizard ready for combat – turns out he reveals a mystery right before dropping unconcious – great for plotfinders!
Starting out with that package deal for each table I recognize that individual challenges will arise as varied as the beautiful people bringing those challenges. So what if your player is off searching (for what???) during combat instead of laying down the damage, healing and support?

First off, I would have the DC of the search be at least higher than the monsters AC. This is because it’s hard to find something when blood and fire are spewing all around. Secondly, I would not have the item revealed until the end of combat. The player might “find” something but it will be as non descript as possible until combat is resolved. “You find a necklace.” That’s it. Thirdly, I would make it a hell of a challenge to get to the item. I’m thinking Indiana Jones reaching for a holy grail, in a crevice of rock WHILE goblins are stabbing into the player. Combat comes to you, because you FOUND the shiny item! Congratulations!

A lot can happen only 120 feet away given ranged attacks. From what I know of predatory wildlife, they like to gang up on loners, wounded and the young, so bring that element of world building into the combat.
The other consequence of leaving the group is that your player story is PAUSED during combat. You step away from the main scenes, then you are off scene and we will get back to you after this situation is resolved.
It’s ok to directly confront a player who seems to be dragging the game down. Whether they are combating during exploration, or exploring during combat, both are wrong time/wrong place. D&D is certainly a collaborative storytelling game requiring a hive mind of teamwork. When you have a “rogue” player who plays … well, a thieving rogue, the flow of the gameplay is thrown and believe me, everyone feels it. As the DM, it’s ok to say, “hello, for the sake of the gameplay, I would like you to contribute to the overall team goal. There is always a time to run away, but make sure the team is on board before doing so.

At the end of the day, I would attempt to find a way for the player’s actions to directly affect the outcome, even if it’s a poor outcome. Dungeon Masters connect the dots of player’s actions into the larger story.