Why is Apple Watch Series 11 so QUIET?

I just upgraded from Apple Watch series 5 to series 11 (Titanium) and cannot understand why I cannot get its sound volume to be anywhere near as loud as it was on my old one. I have turned up the ‘media’ volume to max in control centre and selected ‘louder’ in Sounds and Haptics in the Apple Watch app in iPhone. But to no avail. When on my daily outdoor walk I can barely hear the split times and other voice messages. On my old watch when starting the outdoor walk the watch would emit three clear tones (mid, mid, high as in ‘ready, set, go’); I assumed this had been scrapped in Watch OS 26 as I could not hear them at all, but I just noticed that they are still there, but so faint that they would count as a hearing test. Is there something I have missed or do I need to book a Genius Bar appointment?