Model will only detect one class

I am working on raindrop detection. In total the project will have 25 classes. The training code is as follows:

from ultralytics import YOLO

model = YOLO(‘yolov8n-seg.pt’)

results = model.train(data=“config.yaml”, epochs = 1)

And this is the config.yaml file:

path: ‘C:/Users/Andreas/Desktop/Data’
train: images/train
val: images/val

names :
0: Own Vessel
1: Water
2: Land
3: Sky
4: Severely Distorted Region
5: Other Obstacle
6: Bridge
7: Surface Vegetation
8: Pillar
9: Offshore rig
10: Buoy
11: Surface Animal
12: Swimmer
13: Surface debris
14: Surface Ice
15: Sailboat Sail Up
16: Fishing Vessel
17: Search/Rescue Vessel
18: Towing Vessel
19: Large Cargo Vessel
20: Large Passenger Vessel
21: Human-powered Boat
22: Millitary Vessel
23: Long-range unidentified vessel
24: Motor Vessel

So when training is done (20 epochs) i get the following results :

Why is only one class being detected?? and how can i make it so that all the classes are being included?
Thanks!