Router was mounted into drawer because that way it does not take waluable space on desk and powercord alows it to go only in these two spots.
Well, you're seriously limiting the wireless range by doing it this way. And even if you use any form of WiFi extender, the extender itself will need a decent-enough signal to repeat.
6 hours ago, Sumk said:
but my question is if there is an app/software that could let me use my android/w10/iphone device as an extender with the same SSID, password, and all as my wifi.
No. Whether it's a dedicated extender or a phone app, it will create its own network so as not to interfere with the original network.
Can't the washing machine be reset to use a new network SSID as if you were setting it up for the first time?
The alternative to all of this is to wire in a dedicated AP to the primary router and position it in the vicinity of the washing machine.
The reason for asking the other questions is that these are simpler issues that can be fixed if they are issues to begin with. Some smart devices can only connect to WPA-protected WiFi, not WPA2; in which case you'd need to configure your WiFi settings in WPA/WPA2-compatibility mode.
As for getting a proper WiFi survey, a graphical analysis will determine if there is interference from other WiFi networks in your area. You're in 2.4GHz after all, which makes it highly possible.