Cannot arm/disarm System from Online Portal

[NonTech]

We have a Honeywell VISTA 20P Alarm System and the EnvisaLink 3 installed. For some reason we CANNOT arm/disarm the system using the online Web Portal from our desktop PC. We CAN arm/disarm from the Eyezon Mobile Portal (mobile link - Desktop PC) and/or Mobile Portal App (on our Android phones). If I'm not mistaken, we were able to arm/disarm from our Web login Account in the not so distant past. What has changed recently that prevent arming/disarming from our Web login account (online portal)?