If your device can get connected with other Wifi settings previous set manually or with MobiControl profile, you don't actually have connection problem. It's just a matter of chance or historical connection data and received signal strength that make the scanner pick other stored Wifi profile(s) first.  If you have a lot of profiles pushed, then you just have to be patient and wait for it to try each profile in turn.

Have you tried revoking your old profile that contain the old Wifi SSID & password?  This removes the old Wifi profile(s) at least for some, if not all, devices I've tested in the past.

If the device WiFi is already managed by SOTI then you should be able to simply update the existing network configuration profile with the new details in order for the old SSID information to be wiped out. If SOTI is not managing the wireless configuration however and that information was set in some other manner (eg. manually, through a separate staging app like StageNow, etc) then you can create a network profile that redundantly sets the existing network configuration information in SOTI so that it is then managing the network settings for you. After that point you can modify that same profile to switch the devices from one network to another.