@Nn03
Are these actual RokuTVs (TV with an internal/integrated Roku OS), or are these TVs with Roku devices connected to them via HDMI cable?
Post back with some info/model numbers about the working and non-working devices from Settings/System/About as well as router model number and ISP (internet service provider). Is the non-working device seeing any networks at all (ie. neighbors and such... presuming so if able to connect to your hotspot).
When you "tried resetting it a couple of times", did you perform a Network Connection Reset from Settings/System/Advanced System Settings/Network Connection Reset/Reset Connection?
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