are both modem cabled to the same ISP provider line? how?
If yes, you may have to manually disable DHCP on one of them. You usually would access modem with a computer on the network which access IP 192.168.1.1
Some test to perform if issue persist:
- disable modem B (unplug), connect to modem A
- disable modem A, connect to modem B
- test mobile data (4G) connection when closer to a window: some materials are heavily interfering with radio signal.
For the longest time now I have been experiencing serious connectivity issues with my home internet. We have 2 modems (by the same telecommunications provider) in the house. One is upstairs, one is downstairs. I naturally use the downstairs one as it is closer to me. However, all day long it just keeps disconnecting: when checking my network preferences panel on my computer, the ISP, Internet and server buttons either all go to yellow color or to red. The same happens when I switch to the upstairs modem. When it is really bad, I use my phone's hotspot to connect my computer to the internet. Sometimes that works well, but often even then I encounter the same problem mentioned above. I have heard of modems interfering with each other and sometimes causing such problems, but when I switch to hot spot using my phone (which is provided by another company than my home internet modems), why would the problem persist? Is it my computer? Sometime my wifi seems to work perfectly, on other days I experience literally hundreds of disconnects all day long, every few seconds, even when I am the only person in the house using the internet.