Check the reed switch on gpio15, it seems that it is constant active. Normal voltage on gpio15 should be 3.3V, only when the reed switch is activated it should be 0 V.
I guess that you use a recent Beitian BE xxx, which has now a default baudrate from 115200 baud. The sw for the T-display only checks the GPS for 9600 bd and 38600 bd....
Do you have a older GPS on hand to test this ? I shall take a look at the sw for adapt to 115200 bd, but it wil take some time...
Greetings, Jan.