Getting error on boot "Missing params" randomly

I am randomly getting this error:

Parameters are missing from firmware. You may be running a version of firmware QGC does not work correctly with or your firmware has a bug in it. Missing params: 1:SYS_AUTOSTART, 1:SYS_AUTOSTART, 1:SYS_AUTOSTART, -1:SYS_AUTOSTART, -1:SYS_AUTOCONFIG, -1:SYS_AUTOSTART

I have qgc running, pixhawk disconnected from battery. When I connect USB I sometimes get the error. When I updated px4, I’ve reset all parameters to default and went through all configuration steps. Everything was working ok before I disconnected the last time. After rebooting from Parameters/Tools/Reboot Vehicle the error usually disappears. I am using qgc 3.5.5, px4 1.9.2.

What can I do?

I see that about one out of three reboots results in a correctly configured system according to qgc. Sometimes, I get the error message, but all is green. Usually when I get the error message, the “Airframes” widget reports it needs configuring. So, it looks like some kind of race condition somewhere.

Can I help someone to find it & fix it?