mkchromecast fails to find chromecast device

[asb0656]

I'm running mkchromecast v0.3.8.1 on ubuntu 20.04. I have a TV with built-in chromecast. I can cast to it from an app called "screen mirroring" running on an android tablet and from chrome running on a windows machine. I can't cast from my linux box. In addtion to Mkchromecast, I've tried chrome and vlc. Neither mkchromecast nor chrome can find the chromecast device, while the option to scan for devices in vlc is greyed out. If I log into my router, I can see the tv.
arp -a also lists the device.

[asb0656]

Followup: My TV is called Sarastro.

arp -a Linksys02212 (192.168.1.1) at 30:23:03:0e:90:9c [ether] on enp3s0 LAPTOP-KIADJ334.verizon.net (192.168.1.130) at 98:22:ef:a2:dc:b5 [ether] on enp3s0 BRW441CA857D676.verizon.net (192.168.1.147) at 44:1c:a8:57:d6:76 [ether] on enp3s0 Sarastro.verizon.net (192.168.1.146) at f8:4f:ad:b8:94:52 [ether] on enp3s0

ping Sarastro PING Sarastro.verizon.net (192.168.1.146) 56(84) bytes of data. 64 bytes from Sarastro.verizon.net (192.168.1.146): icmp_seq=1 ttl=64 time=2.23 ms 64 bytes from Sarastro.verizon.net (192.168.1.146): icmp_seq=2 ttl=64 time=0.977 ms 64 bytes from Sarastro.verizon.net (192.168.1.146): icmp_seq=3 ttl=64 time=52.8 ms 64 bytes from Sarastro.verizon.net (192.168.1.146): icmp_seq=4 ttl=64 time=52.1 ms

mkchromecast -t Mkchromecast v0.3.8.1 Selected backend: /usr/bin/parec Selected audio codec: mp3 Default bitrate used: 192k Default sample rate used: 44100Hz. Configuration file exists Using defaults set there

Here I click on icon on toolbar and "Search for streaming devices:

Configuration file exists Using defaults set there :::Tray::: No devices found! availablecc received

[DJCrashdummy]

perhaps https://github.com/muammar/mkchromecast/wiki/FAQ#no-streaming-devices-found may help.