So your drain isnt taking the washer water fast enough

Have you tried drano or liquid plumber down the offending drain line?
put down a couple gallns wait 12 hours then do laundry. your sewer has
a problem somewhere.

you cant just lay the drain hose on the floor it will drain all the
time.

if all else fails obstructing the drain line exit fitting just a little
might better match the washer to the sewer but i would get the plumber
back

If all else fails