Shaw → [BC] Broadband100 download speed only 1-4Mbps - Vancouver

Happens with any type of download (I have an Easynews subscription for testing Usenet speeds). They all exhibit the exact same behaviour. Shaw in-network connections are fine, anything else tapers from full to very slow within about 20 seconds.
I understand the desire to get some specs on server bw and utilization (I don't have any), but the problem is absolutely broad enough that this can be ruled out. *Any* download from *any* source outside of Shaw network during peak hours. I've tried hundred of downloads from wildly varying sources through the last month; they are all the same. Running a Shaw Speed test during these times reports full speed. Starting a new download (or pausing / resuming a current one) resets that download speed back to full, then quickly down again. No problems during off-peak hours, ruling out my equipment or connection.

Cisco DPC-3825 modem in bridge mode.
Linksys E4200 router.

No problems until about a month ago. Actually, I'm pretty sure the timing of it starting lines up with the big server fire in Calgary. Probably just a coincidence, although this is also the time when I switched from BB50 (which always maintained full speed) to BB100 (which tapers to these ~1-4 Mbps off-network speeds in peak hours).

I should also note that my trace-route ping skyrockets during the problem times from 14ms to over 110ms. The entirety of the increase resides in the Shaw router hops (*.vc.shawcable.net and *.cl.shawcable.net).

Happens with any type of download (I have an Easynews subscription for testing Usenet speeds). They all exhibit the exact same behaviour. Shaw in-network connections are fine, anything else tapers from full to very slow within about 20 seconds.

I have done speedtests on my Mac, I did a wireless test and a test without wireless.

I am getting around 48Mbps download. I have a gigabit router Linksys dir 655.

Shouldn't I at least get over 50 Mbps? Because I never have.

Thanks

Well I'm getting the same issue now.

After my modem going down and needing several reboots every other day, it's up now but my hardwired home file server is getting down speeds of 0.19Mbps down and 3.90Mbps up with a ping of 11ms. I'm quite sad.