These three listed images were severely underexposed.
How did this happen? Film loading needs to occur totally by feel. When you have a stack of film, it generally has notches (the notch code) in the upper right to indicate that the emulsion side is face down. That is unless you unload film holders and mistakenly flip the sheets in your stack.
What happens when you load a sheet of film backwards? Film has a backing layer called the anti-halation layer to prevent halos from light bouncing against the plastic of the film holder or camera back. On kodak film, its a blue tinged layer. So when you load your film backwards as I did. You shoot through at least 5 stops of blue filter material. Not so great for metered exposure.
Film punishes the inattentive.