All tutorial examples now updated and confirmed working s expected in ios15.4.1 except for Example 17 (Shower). DEV_Identify.h removed from all examples and optional AccessoryInformation() Characteristics deleted to make examples easier to use and understand.
To Do: Review and update "Other Examples" and add link to Example 19 in Tutorials.md
This appears to be a Home App problem. The problem cannot be fixed by adding in ServiceLabel and ServiceIndex (no impact), nor adding in isConfigured(), nor adding Name() Characteristics. The Home App refuses to render the valves regardless of what valve type. They will sometimes appear, and then disappear from the interface for no reason.
Testing with the Apple's HomeKit Simulator yields the same symptoms.
Gregg