Horizontal flip (mirrored) gets primary display frozen

Good evening! I use Manjaro Gnome on a laptop and two displays: the laptop’s (1366x768) and a TV connected via HDMI (1920x1080). The drivers installed are non-free (Nvidia).
inxi -G outputs the following

  Device-1: Intel HD Graphics 620 driver: i915 v: kernel 
  Device-2: NVIDIA GK208BM [GeForce 920M] driver: N/A 
  Device-3: Chicony USB2.0 VGA UVC WebCam type: USB driver: uvcvideo 
  Display: x11 server: X.org 1.20.10 driver: intel 
  resolution: <missing: xdpyinfo> 
  OpenGL: renderer: Mesa Intel HD Graphics 620 (KBL GT2) v: 4.6 Mesa 20.3.1

and xrandr the following:

Screen 0: minimum 8 x 8, current 3286 x 1080, maximum 32767 x 32767
eDP1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 340mm x 190mm
   1366x768      60.00*+  40.00  
   1280x720      59.74  
   1024x768      60.00  
   1024x576      60.00    59.90    59.82  
   960x540       60.00    59.63    59.82  
   800x600       60.32    56.25  
   864x486       60.00    59.92    59.57  
   640x480       59.94  
   720x405       59.51    60.00    58.99  
   680x384       60.00  
   640x360       59.84    59.32    60.00  
DP1 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 connected 1920x1080+1366+0 (normal left inverted right x axis y axis) 1600mm x 900mm
   1920x1080     60.00*+  50.00    59.94    30.00    25.00    24.00    29.97    23.98  
   1920x1080i    60.00    50.00    59.94  
   1280x1024     60.02  
   1360x768      60.02  
   1280x720      59.81    60.00    50.00    59.94  
   1024x768      60.00  
   800x600       60.32  
   720x576       50.00  
   720x576i      50.00  
   720x480       60.00    59.94  
   640x480       60.00    59.94  
   720x400       70.08  
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

To sum up, eDP1 (monitor 0) is the laptop’s display, and HDMI2 (monitor 1) is the TV.

The thing is that I need the TV picture reflected horizontally, this is, to be seen properly when looked at it through a mirror. This is done by xrandr --output HDMI2 --reflect x,
the problem is, when doing this, the display at eDP1 freezes (I just can move the mouse and do things ‘on the background’, but the picture itself except the pointer is frozen).
The TV display works as expected, and when the transformation is undone (--reflect normal) everything goes back to normal. When I apply any other transformation, nothing of this sort happens.
Thanks in advance!

I encounter a similar (but wider) issue. I’ve described it in Display frozen after sleep/screen rotation/screen off; until switch to other tty then back to normal. In the meantime, If you found solution to your issue I’m more than willing to know it!