Same issue with my TCL 4 series tv, tried the Roku app on 2 different Android phones and experienced the same app crash behavior. Hoping a simple fix in the form of an app update can get pushed out quickly.
I've experienced the same... Ever since, the August 31st update on the roku mobile app I am no longer able to access expert settings because it just keeps on crashing repeatedly. My tcl tv connection is fine and the app even says its connected, I need to talk to an agent about this.
Having the same problem, which is doubly annoying since the expert settings are only accessible through the phone app. Really frustrating that two years after I bought this TV a software update is making basic functionality unusable.