Nothing has changed, it’s definitely on the Airplay compatibility list as shown here:

https://support.sonos.com/en-us/article/stream-airplay-audio-to-sonos

Maybe try a reboot of the local router and the Playbase too and see if that perhaps resolves the issue.

Here too are some suggestions from Apple sources to fix problems with Airplay connections:

• Restart all devices and try to AirPlay again
• Toggle off Bluetooth, or if already off, try turning it on, on the sending device.
• Turn off Cellular Data
• Disconnect from any other Bluetooth devices (like headphones)
• Connect to the same WiFi network access point
• Reset your network settings on your iDevice in Settings > General > Reset > Reset Network Settings
• Disable ‘Private Address’ MAC Spoofing in the iOS Network connection 
• Disable WiFi calling.
• Update iOS, and speaker firmware/software
• Move your devices away from other electronics and closer to the main router
• Renew your devices DHCP lease via the router configuration pages or better still, reboot the router.
• Switch off any Security/VPN software installed on the sending (mobile) device

Fixed. I unplugged my PlayBase to reboot it. Thx.