I have a feeling that OP has been doing this for a while and the problem just started happening.
If that was the case, I have hard time believing failures in lamp coating happens THAT quickly. I'm thinking more investigation is warranted. Use a known good paper. Use a freshly mixed Dektol. Then do a test with safe light on and off. Also be sure NOT to wear anything that generates light.
I'm sort of guessing, OP may have had weird contamination in his Dektol. Either that or he developed an Xray generating organ on his body and fogging the paper himself.