Light Sources do not generate light

So, i was playing in my wolrd with my friends in a private minecraft server hosted by me, then i came back to my house by the night, then i went afk, when i cameback i was in the "dead" screen, it looks like a spider killed me, but my huse was full brighted with torches, then when i enter to the house it was completley dark but the torches were ther (add pic) it annoyed me because i was farming XP and i lost it because this bug let mobs spawn in "lighten areas", please look that up

Sorry for the english, it is not my first lenguage.

greetings mrporkchop0