The jump in speed is amazing! That kind of result (probably somewhere between 43 and 45) ought to be achievable almost all the time.
As every report for your IP Profile remains at 47.43, it looks like there has been no particular re-sync of your VDSL2 connection to the cabinet - no change to FEC, interleaving, speed or (probably) latency.
That is a hint that perhaps the problem doesn't lie in the copper+VDSL segment of your connection (but the errors detected yesterday were certainly significant). Your finding of a dodgy port on the router may be the root cause.
Certainly plugging the PC into different ports on the router shouldn't have any impact, unless there is a fault with either the port or cable.
Perhaps you should try connecting with wireless, and see what happens then...
Wireless is
1. Best Effort Test: -provides background information.
Download Speed
40.46 Mbps
0 Mbps 47.43 Mbps
Max Achievable Speed
Download speedachieved during the test was - 40.46 Mbps
For your connection, the acceptable range of speedsis 12 Mbps-47.43 Mbps .
Additional Information:
IP Profile for your line is - 47.43 Mbps
2. Upstream Test: -provides background information.
Upload Speed
8.28 Mbps
0 Mbps 20 Mbps
Max Achievable Speed
Upload speed achieved during the test was - 8.28Mbps
Additional Information:
Upstream Rate IP profile on your line is - 20 Mbps