Hello Pips_M,
We appreciate your response and providing us this information. Could your confirm if you've tried restarting your MacBook Air in safe mode? We provided you with that article in our initial reply. It’s a way to start up your Mac so it performs certain checks, repairs, emptying of system cache, and prevents some software from automatically loading. Please note that it will take longer than normal for your computer to load. Also, your screen may flash and change colors. Do not be alarmed this is normal behavior when accessing safe mode.
Once in safe mode, check to see if the same behavior continues when placing your Mac in sleep and then waking it back up. Sometimes safe mode can successfully resolve some issues. With this being said, after testing in safe mode, restart and log in as normal to see if that helps resolve the issue.
If the issue is present in safe mode or remains after booting back to normal, we will have you test a new user account next. This can help isolate if this is a user-specific issue, or a system-wide issue. Here’s how: Set up users, guests, and groups on Mac
Let us know the results.
Best!