I have a 20mb uncapped FTTH, where telkom is the ISP and Vumatel is the fibre provider.
I do a speed test using numerous test sites and I get a download speed of about 20mb.
When I do a connectivity check on my DSTV integrated WIFI, I only get about 1mb, if I am lucky.
The speed test on DSTV and via PC or cellphone are all done on the same WIFI APN.
This issue exists all the time and is not dependant on time of month and how much cap I have used.
Note I have uncapped Fibre.