Airplay to homepod dropping when using iTunes on Windows.

I've been having this issue ever since I bought the Homepod about a year ago: when using airplay to stream from iTunes on Windows, the audio will periodically drop out seemingly randomly. It will come back if I hit the "next song" button. Sometimes it comes back by itself after a while. When it drops and I click on the Airplay control in iTunes, the checkmark next to the Homepod has turned into a horizontal line. Ican make it come back if I click the horizontal line and turn it into a checkmark again.

Here are some observations:

• Happens on Windows 7 and Windows 10.
• The Homepod is about 10 ft from the WiFi Router (NetGear R7000)
• When two Homepods are connected, it happens to both of my Homepods at the same time.
• It doesn't happen when I'm using iTunes for Mac, but it still happens if I use iTunes for Windows running via Parallels (Windows 10) on the Mac.
• My PC is connected to the router via Ethernet.
• if I continuously ping the Homepod, there are no apparent packet drops when the music cuts out, so it's still connected to the network. Latency is <10ms, but after disconnecting, latency will increase to >100ms until the audio is reconnected, and it goes back to <10ms.

Here's some things I've tried (unsuccessfully) to fix it:

• Update the firmware for Homepods
• Update iTunes to latest version
• Update router firmware to latest version
• Tested 2 different brands of routers, a modern one from TP-Link and an old one from Cisco.
• Turn off network QoS in the router setting and in the Windows network settings
• Turn off IPV6 in network settings
• Turn off the 5GHz radio on the router
• Turn off the 2.4GHz radio on the router
• Called Apple tech support (got "make sure your WiFi signal is good/software is updated" answer)

Seeing that this only happens on Windows and not the Mac, it seems like either some Windows incompatibility or an iTunes for Windows bug.