I hope you are doing well. I can relate to your words and suggest that this could possibly cause due to supported screen resolution is not being set correctly in the Game.
Please set the screen resolution to normal instead of maxing out and Save the changes to fix this.
If the issue still persists, please make sure to first check if the Game is running as administrator and lower the resolution> exit to RDR2 story mode>launch Red dead Online and revert back to native resolution.
Thank you for being an avid Player. Have a great day ahead.