Quake II - Detention Center enemy count


I´m playing the remaster of Quake II and, like i did with the original version, I want to complete 100% of the game: all monsters and secrets. But I am having problems with the level Detention Center, the second level of the Unit 3. I´m playing on Hard difficulty. And at this difficulty, the enemy count is 51. But I have completed the level, I have searched everywhere and I have only found 48 enemies. I am missing 3 enemies. But I don´t find them. Any help? Is this a bug? Where are they? Thanks.