Bedtime routine broken

My 10 year old used to be really good about going to bed. We had a very rigid routine. It takes him a long time to do each bit but he didn't 8pm screen off, take inhaler, clean teeth. 8:20 I read to him, 8:30 my husband reads to him 8:40 he reads to himself and lights out at 9.

Over the last few weeks this has fallen apart.  He wants to keeping chatting, spouting information about games or videos we are not interested in and refusing point blank to go to bed. He will escape downstairs or go to our bed or try giving us extra hugs or kisses to stop us leaving.  

Every night seems to be less reading and later lights out and settling down. 

Any suggestions on how to get back on track?