Terminal columns/width reported to be 80 columns

[varac]

I noticed that the output of asyncrun is limited to 80 columns.
The following python code determines my current terminal width:

$ python -c 'import shutil; print(shutil.get_terminal_size())'
os.terminal_size(columns=184, lines=52)

But when run with nvim/asyncrun.vim I only get 80 columns:

:AsyncRun python -c 'import shutil; print(shutil.get_terminal_size())' 

|| [python -c 'import shutil; print(shutil.get_terminal_size())']                                                                                                                       
|| os.terminal_size(columns=80, lines=24)                                                                                                                                               
|| [Finished in 1 seconds]   

It could be sth with my setup, but I don't know how to debug/fix this. Or is this a known issue ?