For starters, what model and model number Roku do you have? Settings > System > About will tell you.
If you have a model that only supports connecting to the 2.4 GHz wifi band (notably non-4K Express and Premiere models) be sure your hotspot is set to use the 2.4 GHz band, not 5 GHz.
Roku Community Streaming Expert
I am not a Roku employee, only a user like you. Please, no support questions via private message -- post them publicly to the Community where others may benefit as well.
If this post solves your problem please help others find this answer by clicking "Accept as Solution.".
Ultra 4800 | Streaming Stick 4K+ 3821 | TCL Roku TV 43S245/C107X