Windows 11 Intermittent PC Startup Issues: Freezes, BIOS Defaults, and Login Problems

My PC is not starting up as it should. Sometimes it just defaults to the Bios screen, other times it defaults to the blue sign-in screen but without the p/w box, other times it goes to blue screen and freezes immediately I enter p/w, and sometimes it just starts normally. It can take me 3 -8 attempts of powering down and starting before I can log-in and use the computer. There is a POST bleep most of the times I try to start. The PC uses an SSD. i9.11 and has 80gb Ram and approx 8TB disk space.
Is there a way of fixing this? I have so much on my system I do not really want to do a new install.