It seems I have been able to remediate my sound issues by changing from the Realtek High Definition Audio driver to the High Definition Audio Device. Before this, I would lose sound, run a repair, sound would return and then 10 minutes later be gone again. After several days of struggling with that I decided to abandon the Realtek diver (since there was no Windows 11 Realtek driver) and go with the only other compatible hardware alternative that I could find on my HP 745-G6 Laptop - the High Definition Audio Device. Since using this driver, sound has now remained constantly available.