Having the modem next to an AC vent should have no impact. Those wildly fluctuating power levels are the reason this is a bigger problem... ranging from -9.3 to +1.5 is not normal. Ideally, power levels only fluctuate small amounts from channel to channel...like +- 1 or 2 dBmV total.
Did you just reboot the modem? There is a surprising lack of corrected/uncorrecteds.
Yes, it should be obvious to any tech once they look at that. Now the real question is how well trained or motivated that tech is to be able to diagnose the cause or will he just want to replace the modem and move on to the next house.
Don't give up calling for service appointments. Tell them you are having outages. If you have so many tech visits within a certain timeframe that does not fix the issue it will get the attention of next level support.
Well, I apologize but apparently I assumed too much without asking other roommates here or taking enough time to look over it myself, but this splitter situation seems to have nothing to do with it potentially. The splitter used is only from the DTV service, where it branches off into 3 other receivers, with the 4th one being left open currently, but it has seemingly nothing to do with the internet service. The line from Spectrum initially had a 3 way splitter when we had 2 receivers and 1 modem with TWC and it seems when DTV came out, they removed the two receiver connections from the TWC splitter and just left the TWC 3-way splitter with just the modem connection (this explains why the first tech that came out said there was an unnecessary splitter and removed it and just coupled the TWC line to the modem).
So at this point, I almost consider it a bad thing as now the splitter seems to have no play in what's going on, as the issue was occurring both before and after the unneeded splitter for the Spectrum connection.
As a side note, the power levels on the downstream side seem more normal if I'm reading this right. For the last two nights, I've still been having the issue, but not nearly to the extent of what it's been at, but I still consider it a problem as I had zero issue before.
Either way I apologize for the misinformation originally.
Your upsteam signal appears to be OK, the downstream is not so good. Signal-to-noise ratios under 36 are "poor", in my book, and only 5 of your 20 channels are above 36.
The numbers for your lowest frequency downstream channels (555 through 603 MHz) suggest that there is a problem with the line, probably external to your apartment, possibly due to old traps/filters in the drops to other customers.
It sure would be nice if you could convince your next "home tech" to put in a request to the bucket truck team to adjust the amplifier for your drop to boost your signal by 6-8 dB, as you have plenty of headroom on the upstream side, and that should improve both the downstream power level and the SNR, which should improve stability.
I apologize for the long delay between last posts from myself. There ended up coincidentally being a water leak issue that caused my download speeds and power levels to go down to the -15 db range for a day. Had someone come out and they fixed everything up, but I am still off and on having this same upload inconsistency issue. The last two or three nights, the issue has been hardly noticeable (last night being perfect), and tonight I am back to a large amount of dropped frames and inconsistencies in the uploading side of things.
To me, the power levels and snr seem fine on both downstream and upstream if my own research is correct. I'm not sure if the difference in temperature between the day time and night time and our AC being on at night at the already lowered temperatures is causing some sort of temperature differential issue at night only. To me, the temperature seems to be the only thing varying during the days and nights, and maybe that is somehow causing the inconsistencies in my packet uploads at night. I'm really not sure what to do at this point as the 4th tech only fixed and focused on the download / low power level issue I was having, as again they are unable to diagnose any issues that are only happening at night.