E70 3.0 x5 brake going to the floor
 

I recently replaced the water pump and thermostat on my suv which now has 180k miles. After turning on the car I noticed that the brake is going to the floor. I thought maybe I’ll flush the brake fluid. After putting my pressure bleeder on I notice that there is a leak that’s coming from the master cylinder reservoir. I know there’s no issue with the tool because I bled my brakes yesterday on an e39 m5 and it worked perfectly.

Is my issue with the reservoir or do I need to swap out the full master cylinder as well ? Here is a video of what is noticed:

https://youtube.com/shorts/gbOV97icyZg?feature=share