What version of Citrix VDA are you running on the VM?
We’ve had UDP audio working over EDT but the experience was poor so we disabled that Citrix policy. You can check this documentation here:
https://support.citrix.com/article/CTX220730
Keep in mind the Citrix receiver on ThinOS 8 is a Dell modified version of Citrix receiver from around 8 years ago or so. ThinOS 9 is now using a full Citrix Workspace App for Linux and will be subject to Linux’s limitations.
What is it you’re trying to get UDP audio working with?