CM700 Modem

[xcrmom]

Hello I have been told by my ISP that my modem is not working properly and that it needs to be replaced.  Here are the specs:  Can anyone recommend anything for me to try.  My ISP just increased my internet speed, but the modem gives no where near that speed.  Thank you.

[FURRYe38]

Are you experiencing problems>?

Have the ISP check the signal and line quality UP to the modem. Be sure the ISP provisions the modem correctly.

A couple of correct and uncorrectables but should be causing major problems:
Be sure there are no coax cable line splitters in the between the modem and ISP service box. 
Be sure your using good quality RG6 coax cable up to the modem. 
Be sure to power OFF the modem for 1 minute then back ON.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Mod...

Power looks ok and with in spec:
https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router?article=24311
https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html

Be sure your using a good quality LAN cable between the modem and router. CAT6 is recommended. 
What is the brand and model of the host wifi router connected to the modem?

[xcrmom]

They checked up to the modem and everything is great.  With the modem, downloads are around 80's.

[FURRYe38]

This is with a wired PC connected to the back of the modem? 
Be sure the PCs ethernet adapter is getting 1000Mpbs connection rate at the modem. 

Test with Ooklas installable speed test app on the wired PC.

[xcrmom]

Sorry - Here is the info on the router.

[FURRYe38]

FYI, please edit out any WAN addresses, product serial number and MAC addresses from pictures before posting in public forums for security reason. We've edited your picture for you. 

[xcrmom]

Coming into the home it was great speed.  Once tested through the modem, the speed decreased severly.

[FURRYe38]

Might try a different CM series modem then. CM1000, 1100, 1200 or 2000.

[Kitsap]

Your Belkin F9K1123v1 router design dates from 2014.  In the technology world that is old and it will have a difficult time keeping up with modern cable internet throughput.

https://www.amazon.com/Belkin-AC1200-Wireless-Router-F9K1123/dp/B00JY4QCJQ 

Recommend you also consider replacing the router.