My son and I have a YouTube channel, and have been having lots of Internet issues with our streams lately. We currently have an Omen computer, a new Gateway modem from Xfinity that says we can Download as fast as 400 Mbps. I just ran a speed test and it says DL speed is 337.7 mbps and upload speed is 9.8mbps. The computer is plugged into the modem with an Ethernet cable. We're streaming in 720p, 2.5mbps AAC 128kbps and stream on YouTube in ultra-low latency. And we obviously also use vMix to stream. And over the last month or so we've had a lot of issues. Sometimes vMix won't let us start the stream again, and we also send an error report when that happens. But 3 out of the last 4 nights our show keeps buffering and we can't keep a good signal. I've been assuming this is an Internet issue, but now that we have the best Internet we can get and have good upload speeds, I can't figure out why this is happening. Last night YouTube said the health stream kept going from good to bad, but tonight it said it was good the entire time, but we kept buffering and at one point just went off the air. I checke our streaming logs, but I don't know what to make of any of them. Here is one from tonight. I know it said:

[dshow @ 020c83e0] real-time buffer [vMix Video YV12] [video input] too full or near too full (100% of size: 128000000 [rtbufsize parameter])! frame dropped!

I don't know why we would be at 100%. We use one Computer with an elgato and one with an NDI. But the CPU vMix never went about 45% or so. Does anyone have any suggestions for me? I'm not an expert in this stuff, and am just a dad trying to help his son. I literally don't know where to turn for help.