I have this issue as well. Also using Taxi2Gate OTHH. The following steps used to work on older early access builds of Traffic Global, but this trick doesnt work for me anymore.
Open the airportLookup.xlsx file and change OTBD to OTHH (and delete the incorrect entry that listed OTHH as an airport in Iran).
Note: I have also tried adding a new airport in this list for "Hamad International Airport", instead of changing Doha International Airport to OTHH.
Open TrafficGlobalDatabase.xlsx and change all the departure and arrival entries of OTBD to OTHH.
Compile in TG application, making sure to tick Traffic Global Database and P3Dv4.
This would work perfectly in older versions of TG, but in 1.1.1.1 and later, for some reason there is no traffic at OTHH. Checking the log gives me a million "Unable to find available parking at OTHH.
My hope is that the devs fix this and make it easier to add new airports like OTHH and LTFM.