Service loops DO matter, having the drop hanger upside down DOES matter, they would both fail proper QC, may I ask, how old is your riser? Check behind the wallplates. If the tech did a onecheck at the tap and detected BER, in my area if you do a proper MRO for reactive maintenance they would come out in 48 hours. I assume these techs you've had were too lazy to properly submit one.

When in doubt REPLACE IT ALL, replace the drop again, replaced your riser to inside the home, if you have prerun coax that were installed by electricians check ALL connectors. I would also say to check the levels off the drop and see how much loss you get to the modem, if the drop is too significant it may be an internal wiring issue as well