too-frequent but intermittment connection issues

[juniemae]

I've been having intermittent connection issues for about two months, and it's gotten particularly bad in the past two weeks.

I'm fed up, and figure I must need a service call at this point. But what happens if it's working fine when they come? Can they still fix the problem if it's working when they arrive? Am I going to get charged every time they come out and it's working?

My modoem isn't outdated. I checked.

Thanks

[EG]

Start here;

https://forums.xfinity.com/t5/Your-Home-Network/Internet-Troubleshooting-Tips/m-p/3310447#M316652