I decided to give the macOS Monterey Beta another try. The reason my first try failed is that the external SSD drive died. Yes, SSD drives do die eventually. I bought a new WD Blue SSD (Western Digital Blue) and installed Monterey on that. All seems to be working fine. After I got it going, I updated it to the latest Beta. macOS Monterey is coming along. I am sure that Apple will make the September / October release date.