If you are using Google Chrome or MS Edge to access the ZD, please try using Mozilla Firefox version 92 or newer. We have a known issue with Google Chrome and ZD due to HTTP header size limit. This issue is fixed in 10.5.0.0.190 and above firmware versions.
Thank you for writing to us.
What was the ZD firmware before upgrade?
Could you please elaborate on what you are trying to configure and share any possible error while doing so?
Also, try doing the changes in ZD from Mozilla Firefox browser once.
Will wait for your response.