6 month old stirring through the night and waking at 5am

Re

My baby started sleeping through the night just after 4 months. We now have a bedtime routine which means my baby is usually changed, fed and asleep by 7pm.

However over the last few weeks he will fuss and wake up in the night. Sometimes crying, but most often just seems to be awake. He then wakes up in the morning at around 5am and usually won’t go back to sleep despite lots of eye rubbing, yawning etc. Even if I give him milk.

He is still in the same room as me and I feel exhausted. My partner also gets up in the night so it’s not just me.

Does anyone have any advise for a baby that just seems to fight sleep ?

I don’t tend to him as soon as he stirs I tend to leave him however his cry will just intensify. And I hold off on milk too. Ignoring him while he fusses makes no difference and Iv even tried rocking him back to sleep with his dummy in and again no luck.

Thankyou x