Does it add as a disconnect and leave percentage?

I've done it once it didnt ad anything, then another time it did? I'm confused thx

Yes, it does. Your team may have lost before you got disconnected the time it didn't count. If the other team gets inside your base, you don't get kicked for idling inside your base.

It counts as a dc and yeah like he said, either your team won or lost or conceded before your 5 minute timer ran out.