Internet slower than Spectrum claims - Time Warner Internet

This question is about "Internet slower than Spectrum claims", with Time Warner Cable internet and apps. I just switched back to Spectrum after being with another provider for a year. New install of phone, TV and internet. New modem and new spectrum provided router. I am supposed to have internet up to 400 Mbps. I know it is not guaranteed but I expected something close. When I do a speed test using the Spectrum speed test web page it consistently comes back between 95 and 97 Mbps. I had to call about another issue and while I had the customer service rep on the phone I asked about the internet speed. They told me they could test it. They told me the test they just performed showed I was close to 500 Mbps at the modem. They said with me having the upgraded service they always boost the speed above the expected 400 Mbps to account for loss through the router. They said to test this I could plug my desktop (I am using ethernet cable, not wireless connection) directly into the modem bypassing the router to test the speed. I did that and still received 95-97 Mbps. How can they say I am getting 500 Mbps to the modem but the speed test is less than 100? While the technician was there working on my TV he also told me I had a stronger signal than most on my cable line. He tested the wireless speed and said he was getting about 250 Mbps on his cell phone speed test. I did a speed test on my cell phone over the wireless connection and get about 120 Mbps. That is the other confusing part. How can my wireless be faster than a hard wired connecting. And yes, I changed out my ethernet cable to the 6 foot brand new one that came with the router and received the exact same results. Not the cable. I also question why he claims to have faster wireless connection than me. I am standing right next to him 5 feet from the router.

Internet slower than Spectrum claims?