Yes, indeed something is happening in the parser. So at least it gets to the processing stage as you have a line.
2021-11-24 15:15:56.109 [DEBUG] [inding.miio.internal.robot.RRMapDraw] - Identified rooms in map: 16 17 1 18 19 20 21
RRMapDraw is responsible for rendering the image. The only thing that comes to mind was an issue with the fonts, which was reported long time ago. (somehow java did not see any available fonts in a headless server).
To avoid the text, checkout this post Xiaomi Robot Vacuum Binding - #1895 by marcel_verpaalen mapConfig.json should contain an empty text like this { "text": ""}
You can also try the following { "text": "" , "cropBorder": -1 , "showLogo": false} as that avoids some nastry logic.
Note, your path of the file is somewhat unusual (it does not contain the usual userdata part), I think the mapConfig.json needs to be stored in the same folder