Router speed much slower than Modem Speed - Time Warner Internet

This question is about "Router speed much slower than Modem Speed", with Time Warner Cable internet and apps. I have had a modem provided by spectrum for about 9 months. At the end of April I purchased a TP Links router and set it up to my 8 year old laptop. Speeds were pretty much the same when I was accessing the internet via wifi or an ethernet cord. Whether I used it in my kitchen or bedroom, it was fine.

In July I purchased a brand new laptop and loved the amazing speeds from my router again in my bedroom and kitchen.

About two weeks ago I noticed unreliable speed and incosistency in quality speed when I went wireless. On Thursday, my wireless completely stopped working. I unplugged both the modem and router and it did nothing. After 30 minutes on the phone with spectrum, the operator said he saw nothing wrong with my modem so it must be my router. I do not have a ethernet port in my laptop so I had to believe him. I spent 30 minutes on the phone with TP Link support and they had me set-up a DNS number and secondary DNS number since none were showing. My internet bars became visible but there was a yellow triangle which rendered my wifi inoperable.

I called back Spectrum were I spoke with a woman for an hour who said it was an issue with the service. I pay for 200 MBPS and my laptop was reading less than 1 MBPS. She did some tweaking on her end and we got it up to 10. She had me remove the DNS numbers TP Link support had me enter stating that it should populate automatically. She sent a tech to come out to my home and swore it was the router and not the modem. I called TP Link back and they said it was the modem not the router.

The tech spent about an hour in my home and was able to gain a reading of 238 MBPS off the modem. I did a factory reset of my router and was able to get a wifi reading of 20 MBPS on my laptop. Today, a day later, I can only access my regular wireless line and not my 5G at a speed of 40MBPS.

Why was my laptop over wifi only reading 1 MBPS on Thursday and now 40MBPS. And why not 100 MBPS. The second spectrum operator said at minimum, I should recieve wifi at half the speed of my wired which apparently is over 200 MBPS.

I did a quick speed test and registered 20 MBPS on my wireless and 92MBPS wired on my old laptop.

Router speed much slower than Modem Speed?