Windows MC7700, Cellular APN Settings and sending SMS using C#

I posted a couple days back with regards to getting my MC7700 to change modes and have access to the Serial ports. Link to old post: Windows MC7700 how to change to use serial? - #2 by jyijyi.

Long story short after trying a few methods I got it to recognize the serial ports.
Currently have two that popped up: DM Port as well as NMEA Port.

My issue comes in now with the cellular as it either just disappears on windows or pops up but won’t connect due to APN settings (Tried several confirmed ones from provider) which non worked. Is there a way to have both the serial and cellular work?

Lastly my main goal is to use the module to send SMS’s through a program however, neither comport seems to be working. Is this due to the cellular? or perhaps my AT Commands?

Below is a portion on my code used to run the AT Commands most seem to be support as per the documentation however still does not send SMS’s.
Debugging has been tedious as running Visual Studio on the SBC is painful so can’t identify where the problem may be.

Code: spSms.WriteLine(“AT+CMGF=1” + Environment.NewLine);
ResultCode = spSms.ReadExisting();
spSms.WriteLine(“AT+CSCS=“GSM”” + Environment.NewLine);
spSms.WriteLine(“AT+CMGS=”" + phoneNumber + “”" + Environment.NewLine);/
spSms.WriteLine(NoInternet + Environment.NewLine);
spSms.Write(new byte { 26 }, 0, 1);
UpdateScreenOneText("Offline SMS Notification Sent to + phonuNumber);

NOTE: This code worked well when making use of a mobile Wi-Fi router to which I just plugged into the PC and was able to access the serial port.

Great thanks in advanced! Apologies if question may seem unclear completely new to using IoT Modules so I have limited knowledge from what I have been able to research.