I'm running into the same issue. 75/35 but uploads are never where they should be. Downstream is perfect though.
It was fine in the past but has been acting up as of late; possibly the last several months.
I've been working with Verizon support for ~4 weeks now to get the issue resolved but it feels like I'm running in circles.
They're definitely working with me on it; I'm confident it's more an issue with something on their end and not mine due to all the things we've done and tested up to this point. (Already got a wall of text so won't detail all the steps we've gone through unless someone wants me to)
Upload speeds always slow down during late morning to evening time; dead of night and early morning are always fine (not 35Mbps but ~30Mbps which is acceptable) leading me to believe it's a BPON oversaturation issue that shows up during peak/prime time hours.
Now I just have to convince them to take a look at it.
They keep getting me to do the same basic troubleshooting steps so I feel like it's a different technician/NT every day instead of it being one person/team taking ownership seeing things through to resolution which is a bit frustrating.
Here's to hoping it gets solved soon. I work on an IT help desk myself so I'm doing my best to be patient.