Very Slow to almost no Yaw after Recalibrating and no battery indicator

I am a complete newbie. We purchased a Monarch quadcopter with BirdX to control seagulls at a resort.
Drone was working perfectly until I linked to Missionplanner.
I followed tutorials to load firmware etc and recalibrate and have almost lost all yaw function.
From what I can tell the copter is performing fine except for this.
I have no idea what I am doing wrong or right actually and have no technical experience with configurations etc.
When following the tutorials there are mismatches between the tutorial and the missionplanner dropdown options
Apart from the tutorials I also tried the Wizard option but still the same result.
I also have no battery information on the HUD and no idea where to look to rectify this.
Having no luck from Monarch technical support…very frustrating.
Really need help from start to finish on this please