Unable to Use Special Characters when Setting Basic Captive Portal on Insight Web Portal

[Sololion]

I am setting a WiFi network with organization-wide SSID enabled using Insight Web Portal.

When I try to enable the Basic Captive Portal, an error message "Only alphanumeric characters and special characters !"#$%&'()*+,-.\/:;<=>?@[]^_`{|}~ are allowed".

With further checking on my EULA, the portal declines any special characters listed in the mentioned error message be included in my EULA. 

In another word, the system allows my to use "By using the WiFi service provided by our organization" as my EULA, but prohibits me to use "By using the WiFi service provided by our organization,". The last "comma" trigger the error message. Maybe this is a bug?

[schumaku]

Yes, something must be broken on this input check.

Almost tempted to state none of these chracters does pass ... !"#$%&'()*+,-.\/:;<=>?@[]^_`{|}~