Safari 15.3 - unacceptable bugs using MacBook Pro

Using Safari 15.3 leads to repeated crashes while Safari is open, and each time I close the computer after using Safari 15.3, I am automatically logged out and have to reboot. Neither problem existed before I upgraded to Safari 15. Long story short: I've given up on Safari 15. These problems don't happen with Firefox or Chrome, making Apple's browser the worst option available for use with Apple's laptops.