The apple brand itself announced it. The bug that prevents the correct display on the external screens of MacBook Air and Pro equipped with the M1 chip will be fixed in a future update of macOS. This bug only concerned ultra-wide and super-ultra-wide screens, of which certain screen resolutions, which however had to be supported by the computer, were ultimately not.
Apple hasn’t given much more information yet. It has simply been indicated that everything will be back to normal with a future update, without announcing how long it will take.
How to choose your screen resolution?
To go to the different resolution capacities of your computer, you have to follow the path: System preferences, then Monitor, you can then choose “Default setting for the screen” or “To scale”. If you choose the second option, you can then choose the different resolutions offered by your screen and which are supported by the computer.
Today, the new MacBook Air and Pro which are equipped with the new M1 chip are able to support one or two external displays. If this is less than on older versions of Apple computers, customer feedback for these MacBooks has hardly ever mentioned this drop in the number of external screens, two sufficient for the vast majority of uses.
If, despite everything, some people want at all costs to increase the number of screens around their MacBook. There is a workaround, detailed in the linked article.