Why do we play so much worse as a squad, even though we’re decent solo?

Hey everyone,

I’ve got a question for the community because we honestly can’t explain what’s happening.

Whenever I play together with my squad (friends), we get absolutely destroyed — doesn’t matter if it’s Breakthrough or Conquest. We barely get any kills and feel completely useless.

The weird part:
This happens only when we play together.
When each of us plays solo, we’re average to slightly above average players.

Our solo stats:

K/D between 1.3 and 2.0

Usually Top 10 in Conquest

Example round: 23 kills / 13 deaths / 30 assists / 8 objectives captured

As soon as we queue up as a squad, nothing works anymore.

Last night we tried the Winter mode and just got insta-killed by SMGs nonstop. Two squad members ended up rage quitting because it just wasn’t fun anymore.

Does anyone know why this happens?
Is it matchmaking, squad MMR, playstyle issues, communication, or something else?

Thanks!