I have just recently had Fiber internet connection installed and they gave us Huawei HG8245H as our modem/router. Wired connection is very good however, the WiFi isn't. From 9pm to around 10am connection via Wifi is ok but after that, the internet via WiFi stops. Then goes back again after a few mins, then stops again. In the afternoon it just gets worse because the internet just stops for a few hours, resumes for about 5 secs, then stops again. It goes on until around 9pm-10pm, then the internet just resumes back to normal. All the devices that are connected via WiFi experiences the same issue (laptop/smart phones, etc). And while this is all happening, again the wired connection is very good all day. I already did troubleshoot WiFi but to no avail. Apparently, the internet connection is OK because LAN connection is good. This has been going on since the beginning.
Is there anything else I can do to the modem/router on my end? Could this mean that the modem/router is defective? Is this issue only resolvable in our ISP's end? Thank you very much for your answers.