Gigabit upload speeds slow

[Nr0803]

I have gigabit internet. It started in February, after 9pm my time upload speeds are 1 - 2 mps. During the day up until 9pm it is 35 - 40mps upload.
3 techs have come out ( during the day) and everything is fine.
I have connected to hotspots in my neighborhood and the upload speed is 1 - 2mps after 9pm.
Many tickets have been opened even an ER1 without resolving the problem.
Tier 2 can see my speed-test using xfinity speed test website, so they know about the problem.
Can anyone help?

[bald271]

The symptoms appear to be 140% consistent with "uplink is oversubscribed" but also consider that the speedtests are somewhat 'self-spoofed', and that any user/endpoint app(s) which you are using to test may be throttled by the destination/server/far-end/protocol, and not by your ISP.     Either way, possibly consider to drop to the tier with 5Meg upload and save some money.   Even at that 5Meg price you can get some money credited each month the uplink does not meet the 5Meg/whatever service-level-agreement.