Hitron CODA56 Docsis 3.1 modem getting less than 2mbps upload speeds

@tennisace01​ My previous modem was the s33 and was rarely able to get above 15mbps upload speeds with it.  It is not capable of the next gen plan upload speeds. (well, let's be honest, it's fully capable of it, xfinity and others refuse to adopt proper firmware for it to achieve the higher speeds).  So I bought this Hitron Coda56, which is on their approved next gen list, but they keep wanting to blame the modem.  I have a screen shot of the modem's dashboard clearly showing the OFDMA upstream channels are disabled.  That's 100% on comcast's side.  They have complete control over the firmware and the provisioning.  It took me 2 different "techs" to finally get the modem reprovisioned, and took a 3rd to listen to me when I told them the firmware needed to be updated as I am on a next gen speed plan, the 4th tech was completely useless and wanted to send a tech to my house as the only option, and the 5th finally at least claimed to have verified that it was correctly provisioned and had the newest firmware.  He then proceeded to spend 5 minutes trying to get me to take a comcast issue modem, which I refuse to do.  And his last resort was "the modem is bad, send it back".  Which is entirely possible, but not probable.

I know with the s33, the uploads are advertised as 35, but prior to a couple days ago, I was consistently getting 40 for many months, which for my purposes was fine. I am on a next gen plan but because I was fine with the 40ish I was getting, I decided not to spend $200 to get the S34. Now I fear the tech will blame the modem tomorrow night (we'll see), but I've read on here people having all sorts of problems getting the next gen speed with s34 as well, even though it's on the list. So that's not a clear solutions either. 

@tennisace01​ Yeah, I never hit the advertised upload speeds with s33.  And after they did "maintenance in my area", it got even worse.  I was barely hitting 12 to 13mbps upload speeds.  I was still on a pre-next gen speed plan, so I bought a new modem, and switched over to the next gen speed plan which is supposed to be 1100/110 or something in that range, and I'm now hitting over 2300 down and 2 up.  

The only reason I went to the s33 a couple of years ago when I did was because my previous arris modem (the model number escapes me) was really blowing a gasket and throwing speeds all over the spectrum and randomly cutting out and refusing to reconnect without multiple reboots.  Considering it was several years old at that point, I chalked it up to equipment failure and replaced it with an S33.  Which was its own nightmare.  I even had someone at comcast (you know, back when you could actually SPEAK to a PERSON on the PHONE) tell me my "house was leaking signal" and a tech had to come and diagnose it.  Um.. No.  That's not a thing.  And no, a tech is not coming into my house and touching my equipment.  Ultimately I solved it with a signal boosting conditioner and it leveled out my signal and stopped getting drop outs.

This time, I just can't get anyone to actually listen to me.

@user_33sfh2​  I think this is my 3rd modem in this apartment. All Arris. But my hands are unfortunately tied right now. It can literally take hours to get a person on the phone, trying every combo of prompts, and all they are going to do is what everyone else did today--have my restart it over and over, go through their troubleshooting steps, provision it, etc. I unfortunately have to see what the tech says tomorrow night, but I'm not holding my breath for a miracle. Something in particular is going on with the upload speed on my end (like in your case). My plan is 500/100 but I've always gotten around 650/40 (the S33 doesn't get next gen upload speeds and is advertised as 35 for upload, which I was slightly exceeding).  I was fine with 650/40 but I'm not fine with 650ish/1ish...which is what started happening today and then the download speed at some point decreased to 1ish as well. Might as well get AOL dial up at this point. 

@tennisace01​ I don't know if this is the answer for you or not, but I fixed my issue today.

A couple of years back I had a HUGE issue with signal strength fluctuation causing drop outs on multiple downstream channels.  Banged my head against it, replaced my modem (when I went to the s33) re ran every cable line in the house, cut out any extraneous extensions not needed, repaired the outside tap by bringing the main line directly into the house, insulating and isolating the main drop to the house, and I eventually landed on adding a signal booster/conditioner to the drop on the inside of the house and tapping off that.

That fixed the problem for me.  Leveled out the signal strength, boosted it to the correct signal strength and conditioned it to be more constant.  No more drop outs or dropped packets or channel degradation.  It even fixed the intermittent issues I was having with the actual cable TV that prompted multiple box replacements.

Until the most recent rounds of "scheduled maintenance", which i assume were to accommodate the next gen plans.

Today I removed that signal booster/conditioner, ran the line via a coupler directly to the modem drop and VOILA.  Suddenly I'm getting 2300 down and 300 up.

I say all that to say It may be the splitters.  And if you live in an apartment, you probably don't have any access to or control over that.  (I'm old enough to remember running into this many moons ago when they first started adding cable internet and all the existing tv only splitters had to be replaced, and then again to accommodate digital HD TV signals, so it doesn't surprise me that once again the splitters may be the culprits, which would also explain why they are trying to force an onsite technician down everyone's throat.)

If you haven't already, try running the drop directly to the modem if possible, and avoid any splitters in the apartment if possible.  Again, your issue may be out of your control and on some junction on the outside you can't get to.

Good luck!