Downloaded the current version (Dec 2019) and found the same slow speed.  Fixed
it by going into the SET OPTIONS screen (button available on the 2nd or 3rd
screen in when starting a project)

Then - Limits - Max Transfer Rate
 - The default numbers are all tiny, I clicked on the biggest that happened to
be 250000 B/s and then just added a zero to bump it up to 2500000.  Seemed to
fix the problem.