Replaced My Brake Booster, And Now The Starting To Brake Takes Effort

Hey guys! Just last week I noticed my brake pedal being hard when I started the truck, There was also some whistling noises that were happening when driving, pressing the brakes would stop the noise instantly, and after doing some digging I came to the conclusion the brake booster diaphragm was failing. Swapped in a new booster, check valve and vacuum hose today, and now I’ve got a small issue.

When I start to press my brake pedal, it’s stiff, but once the brakes actually engage it becomes smooth like normal, kind of difficult to describe, but essentially it feels sort of stuck before it gets into the full brake swing. Has anyone else run into this, or have an idea what the issue might be?

Thanks in advance for the help!