Looking at your equipment list, you're using an antique N band router which was outdated ages ago. Today's devices are generally designed with WiFi radios that connect A/B/G/N/AC and in some cases AX technology. I'd suggest you replace the router with something more current that at the very least supports the AC band which is MUCH faster and has greater range than the N band in yours.
That said, the MOST common cause of dropped signals is WiFi channel congestion. And how you know, is by installing a network analysis app like WiFi Analyzer for Android or something similar for IOS. Once you install it, look at the graph which will show your SSID for both 2.4 and 5 gHz bands. If unfamiliar SSID means Secure Socket ID which is the name you've given for yours. The app will also show which channel your on and how many others use it. 2.4 has greater range but is FAR slower than 5 gHz. Regardless what's needed is to identify the congestion on the channels you've chosen and if crowded, change the channels to those that are less used.
I hope that helps
Power User (film maker)
Mill Valley, CA
Jonathan
Roku Ultra 4800R; LG OLED55B7A, ONKYO TX-NR636, Panasonic Blu Ray, Definitive Studio Monitor 450 (L/R), Definitive LCR 2000 (center), Definitive 10" sub-woofer, Definitive surrounds. Motorola MB8600 modem. Asus RT-AX68U WiFi 6 router. Western Digital Power Line network adapters
