@JohnDS 

First you need to find out which modem models your ISP supports as you need to use one they support.

Pick one from a higher speed tier, if listed that way.  More up and down channels is better. DOCSIS 3.1 is a bit of future proofing is better to have.

I assume you rent the modem from the ISP, so you would save in the long run. 
 

not sure if that would prevent the hotspot.

@ArcherC8 

Thank you for the reply.  Sorry for the late response as I got hurt at work.

I am completely aggravated with my isp.  My internet goes in and out everyday.  When I call them they go through the basic trouble shooting steps only to waste my time by making me unplug it and wait a minute, just to tell me everything is fine.  Then they tell me if they send someone out and the problem is not on their end, it will be a fee.  I'm so sick of this.  What can I do to solve this problem?  Would the problem most likely be their modem or my router.  When the wifi goes out,, I turn everything off then on again, it works fine.  But eventually it happens again.  This seems to happen mostly at night but sometimes during the day.

@JohnDS 

It can be very frustrating when you have Internet issues.

I like to divide the issue and determine the cause.

I have my own separate router and modem. When I have issues, I connect a PC direct to the modem bypassing the router to see if the issue occurs. If so, I know I have an issue with the ISP, the modem, cables, or the PC. Then I try a different Ethernet cable between the modem and the PC to eliminate it. Then I try a different PC to eliminate it as the issue.

Assuming it still fails, I then look at all the connections starting at the back of the modem, all of the drops, all the way back to the connection coming into my house. What I am looking for is corrosion, broken wire, short center wire, loose nut, and such. Not only does the center wire make a connection but the twist nut does also. Unscrew each, check, clean if need be, and reattach it. My house is wired for both Internet and TV coming in on the same line. I dropped the TV service from my ISP, so I replaced the ‘T’ connector with straight through connector so there would not be any dead drops as they can cause issues. Best to have a wire from the drop outside all the way to the modem with no connections. If you were having any TV issues from your ISP, then wiring would be a focal point. Those wire connectors are known to cause issues.

While a new modem may help, most modems as very solid and do not cause any issues. Consider getting one from a company that has a good return policy and see if it solves your issue. Note that service providers do not support all modems, so get one that your service provider supports. Get one for a higher speed tier. The down side to having your own equipment is the ISP tends to point the finger at that equipment.  

Maybe StarLink may be a solution.