@mritenou
Are you sure you have had the Roku Express 4k+ (3941 ) for three (3) years? (only released last year).
Settings/System/About will tell you the Roku model number of your devices.
Post back with Roku model numbers, router model number, and your ISP (internet service provider).
Also, are you seeing any error messages on screen? Are these your only Roku devices, so we can rule out other connection issue possibilities.
Roku Community Streaming Expert
Just another Roku user... I am not a Roku employee.
Insignia RokuTV, Ultra 4660, Premiere+ 3921, Express 4k+ 3941, Streambar 9102