I have reported this also to CW, and I notice that the same happens on Afrihost/MTN, this was not like this before, something has changed.
Tracing route to speedtest.mybroadband.co.za [196.10.98.18]
over a maximum of 30 hops:
1 <1 ms <1 ms <1 ms jannie-router.home [192.168.1.1]
2 * * * Request timed out.
3 12 ms 11 ms 13 ms cdsl2-ctn-vl2473-ipc.ip.isnet.net [196.38.72.194]
4 10 ms 11 ms 10 ms vlan2473.cdsl2-ctn.isdsl.net [196.38.72.193]
5 10 ms 11 ms 10 ms 196.35.115.136
6 11 ms 11 ms 11 ms mi-za-cpt-p7-te0-7-0-0.ip.isnet.net [168.209.2.12]
7 167 ms 170 ms 168 ms 168.209.246.1
8 157 ms 157 ms 157 ms 195.66.226.134
9 176 ms 175 ms 176 ms jhb-br-r2-gi0-0-3906.frogfoot.net [41.85.1.83]
10 176 ms 177 ms 177 ms jhb-cor-sw1-vlan3902.frogfoot.net [41.85.0.99]
11 175 ms 176 ms 176 ms teraco.co.za [41.206.220.141]
12 176 ms 176 ms 176 ms 196.10.98.18.teraco.co.za [196.10.98.18]
Trace complete.
Tracing route to speedtest.mybroadband.co.za [196.10.98.18]
over a maximum of 30 hops:
1 * * * Request timed out.
2 10 ms 10 ms 10 ms 41.181.51.181
3 11 ms 10 ms 9 ms 41.181.51.182
4 10 ms 9 ms 44 ms tb-dca-2.za--qux-c.za.mtnbusiness.net [41.181.198.188]
5 10 ms 10 ms 10 ms compj-cpt-1.mtnns.net [196.44.18.2]
6 154 ms 153 ms 154 ms ls-cr-2--tb-cr-1.uk-b.mtnns.net [196.44.31.113]
7 153 ms 154 ms 153 ms ls-pr-1.uk--ls-cr-2.uk-a.mtn.net [209.212.111.201]
8 174 ms 173 ms 186 ms 195.66.226.134
9 179 ms 179 ms 179 ms jhb-br-r1-gi0-0-3906.frogfoot.net [41.85.1.82]
10 179 ms 179 ms 180 ms jhb-cor-sw1-vlan3902.frogfoot.net [41.85.0.99]
11 360 ms 360 ms 359 ms teraco.co.za [41.206.220.141]
12 322 ms 322 ms 322 ms 196.10.98.18.teraco.co.za [196.10.98.18]
Trace complete.
Mybroadband uses a server I think that is located in Terco which is 196.10.98.18 for the JHB server.
IS does not peer there so the traffic goes to the uk and back causing the latency.