I'm sure you've tried A to Z so I'm just gonna make a list of possibilities ✨️ -is it time to up the bottle nipple size? -do you use blackout curtains -do you turn off majority lights in home to make them drowsy/ 'Set the Tone' at 7pm -Have you tried 7pm bedtime or 9pm instead? -when do you wake with baby? Is it 4-6am? When waking I'd open black out curtains 3-4mo they are now becoming aware of day VS nignt!! This is why they recommend to 'sleep train' around 4-5mo -Is baby too cold/hot? -are you swaddling? -is there a sound machine for 12 hours at night? -is there any pest control box's In your basement or attic, these emit a high pitch tone we can't hear but babies can.
Do you put baby down & pat their bum or put them down drowsy but awake?
We had something similar but around 7pm and we realised we werent paying attebtion to his wake windows. As soonas we did we realised 7pm was his bedtime as he was knackered. Also had to start planning naps in line with his wake windows and it was solved overnight. Not sure if it will help you but takingcarababies.com has a free blog which addresses each months for babies sleep needs which is what we followed. So making sure baby is getting enough but not too much sleep in day and feeding enough in the day etc
It could be witching hour. My toddler had that for a few weeks during that time.