Part 1: Not enough time

Plate 1F has not been in the chamber for long enough. The solvent front should be about 0.5 cm from the top of the plate when you remove the plate from the developing chamber. This ensures maximum separation of the different spots. You can see that the spots are clustered close together when you take out the plate too early, making it more difficult to distinguish between spots.

Next time, wait until the solvent front has reached within 0.5 cm of the top of the plate before removing the plate from the chamber.