14 month old suddenly having trouble settling to sleep. Help.

[SilveryMoon]

Ds2 has mostly always been fine being put down to bed. Quick bottle and then straight in cot and I'd walk straight out of the room and all would be fine.
The past few nights he has been screaming and won't be left.
What can I do to help him?
Ds1 went through this and I spent about a year laying/sitting on the bedroom floor until he went to sleep. this was difficult to get out of and not sure if it's the best choice this time.
Ds1 and ds2 share a bedroom.
Any ideas?

[peggotty]

Molars coming in?

[peggotty]

Or any teeth, just seen he might not be old enough for molars

[SilveryMoon]

Maybe, but he's ok through the day and up until bedtime.
He also stops the minute I walk in there