Fresh toon rating issues

Recently leveled an alt, did a shuffle (1st one the lobby had all 0 CR, 1780 MMR so thats baseline). Went 5-1, and immediately im at 2050mmr. Cool.

Flipside though, when healing at 2-2100 alot of games ive gotten a DPS with one or two lobbies done who only have dmg buttons bound and go 0-6 making healer insta 3-3 most games.

I didnt play DF but was mmr normal to insantly put people to 2-2100mmr after one lobby on a fresh toon? I thought mmr typically started at 1500