This falls under your HDMI-CEC settings, also referred to as Anynet+. This allows for 2 way communication between your TV and the HDMI device, so when one is turned off or on, the other will respond. Settings for this are often split between the TV and the external device, so you can have them work one way only.
You can disable Anynet+ completely through Settings > Connections > External Device Manager > Anynet+ > Turn off. Please note: this will affect eARC and ARC devices that are connected along with unified remote control. If you use this feature for other devices, then we suggest checking in with your GPU manufacturer to see if this can be controlled on the graphics card itself, as well as speaking with Microsoft for Windows 11 configuration. Unless some of our helpful community are clued up with Windows 11 and GPU's.
