Manually adjust your brakes........
Jack one wheel at a time off ground
Remove plug in brake slot....inside/lower area of drum
Using a wide blade flat screw driver turn star wheel to tighten brake shoes while turning tire until tight
Then backoff on star wheel until tire rotates 3/4-1 turn freely with slight drag noise of brake shoes
When energized magnet 'sticks' to face of drum and as wheel rotates the magnet travel engages lever which forces brake shoes outward to contact drum.
Magnet/lever only has so much travel and if brakes shoes are not adjusted they can not fully engage drum.
Should adjust yearly/12,000 miles.