is he maybe getting too much sleep during the day or waking up later in the afternoon so that when bedtime rolls around he is just not as tired. If this is the case then maybe wake him up half an hour earlier from his day sleeps or do something in the arvo to tire him out and use up the energy like have a little play outside before dinner chasing after a ball or after dinner. At 10 months old you could plonk him down on a blanket (even though if he is crawling he probably won't stay there) with some toys and stuff, a change of scenery might be enough to get him a bit more tired because there is more too look at.
Otherwise just follow his cues for now and slowly put him to bed a bit earlier every few days and eventually get to a time that you are happy with...