Why so many Monolith in Radar?

I have switched off the Brain Scorcher and returned to Radar, met Syak and done a quest for him.
Radar continues to spawn new Monolith whenever I pass through the area which I have to battle with.
Also as soon as I enter the Pripyat level I am met by a group of hostiles moving through the trees towards me from the street.
I don't remember this in previous playthroughs so this a new feature or is something b*gg*red up in my game?

Did you visit the Wish Granter after turning off the Brain Scorcher? You shouldn't meet Syak until you have done that. From then on you shouldn't meet many Monolithians in Radar or Pripyat unless you failed to clear them out on your first visit. Are you sure the ones in Radar are Monolith and not Zombified Stalkers or Bandits? Either way, as long as it doesn't become a problem I would just continue playing...

No. I went back to other areas first to tidy up a few quests. That may be my problem.
The respawning are def Monolith in groups of five or so.
I’ll have another go as advised. Thanks for your reply

EDIT: Replayed Radar and Brain Scorcher through from start again and this time everything followed the script.
Something in the previous playthrough glitched the game but all well now