High volume when connecting iPad to TV via HDMI

When connecting my iPad to a hotel room TV last night (using Apple’s USB-C Digital AV Multiport Adapter), the volume nearly blew me out of the room.

The TV volume control had no impact, nor did volume control on the iPad. I tested this with multiple apps (Max, YouTubeTV, and others), all getting the same result.

Another user asked about the anomaly (thread found here) and was reminded that connecting via HDMI resulted a “fixed” volume level that could be controlled by the TV. Okay. Cool. I “get” that.

In the past, this set-up has worked—I’ve been using this the road for years, here and abroad, always able to adjust the volume with the TV remote. When I fired up the iPad last night, though…?

Let’s just say no one on the fourth (and, possibly, third) floor of a hotel expects to hear a fleet of helicopters taking off at 10:05 p.m.

Any suggestions about what the heck went wrong (and, hopefully, how to resolve it)?