Lower possible screen resolution on MX Linux than Windows

I'm running MX Linux and Windows on the same machine. I'm using an LCD television screen connected via HDMI to the graphics card (NVIDIA GeForce RTX 2070 SUPER). **My problem:** - On Windows, I can select resolutions way higher than 1024x768 (i.e. 1920x1080 and above). - However, on MX Linux, 1024x768 is the highest resolution (800x600 and 640x480 are also selectable). - Display settings in MX Linux only show one screen labelled "default". **I tried:** - using xrandr as described here . - "xrandr --newmode (...)" gives the error(/warning?): "Failed to get size of gamma for output default". - "xrandr --addmode default "1920x1080_60.00"" also gives "Failed to get size of gamma for output default". - "xrandr --output default --mode "1920x1080_60.00"" gives the **additional** message: "Configure crtc 0 failed". - no change in display happened after that. - using arandr (GUI) *after* typing the above commands: - "default" is shown as screen - right-click --> resolution: shows the 3 resolutions mentioned above, *and also* "1920x108060.00" - selecting "1920x108060.00" and hitting the check sign --> pop-up error message: "(...) error code 1: xrandr: Failed to get size of gamma for output default" and "xrandr: Configure crtc 0 failed". - no change in display happened after that. I would appreciate any help. It is kind of inconvient having to work with this low (and stretched!) resolution on a 42'' LCD TV screen ;)