I'm on 6.48.1 on a 1100AHx4, I've also tested on a rb750gr3 and it seems the same.
I've noticed that if I set a queue to manage bandwidth, it adversely affects the Bandwidth Test tool.
I have a 150 Down / 30 Up link and Bandwidth test seems to be able to measure the upload ok but download is reported as 236Kbps!
Running a Speedtest on a client computer gives (queues are on):
If I turn off queues:
Thank you @TomjNorthIdaho & @Garrison1701 for providing the servers!
Anyone else notice this or is it something I'm doing wrong?