Wifi stops working randomly unless restarted, wired works without issue

[DuckSleazzy]

I am facing this issue since months where my wifi will randomly stop working unless I restart the router, and when this happens the wired connection (Desktop) works fine. I have about 5 devices connected at any given time (4 smartphones all times, and either a PS4 or a laptop). All devices will stay connected to wifi but cannot browse and sometimes the connection drops too, giving an "Incorrect password for XYZ" on my iPhone, "Obtaining IP address..." on Android devices, and "Cannot connect to this network" on Windows laptops. I got my router in March 2019.

 

Router: DLink DIR-816
Router has a patcher cable going in the WAN port from a device (I dunno what that is, can provide images) that ISP installed when replacing my line with a fibre line. That device has another cable going in from a second device (again unknown, can provide images) which has the main ISP's cable plugged in. ISP's cable come in from a (I think unmanaged) switch.
Laptops: Lenovo Ideapad 320S, Lenovo Ideapad S145 (both on latest Windows 10 Pro)
Phones: Two iPhone XR, iPhone 7, Oppo Reno Z 2 (All devices updated)
Desktop:
Motherboard: Gigabyte GA-H110M-S2 (latest BIOS)
PSU: Antec Earthwatts Gold Pro 750W 80+ Gold
OS: Windows 10 Pro (Updated)

Will buying a higher end router help? Thanks in advance guys.

[Bombastinator]

Some routers do a channel search whenever restarted.