Children strive on routine. Well most do.
I would suggest that you try to find as many "triggers" as you can to show the child that it's bed time.
On TC, there is a song sending children off to bed. That could be the start, then the process should be exactly the same each night, Song, brush teeth, use toilet, into bed, read a story, sing a good night song, cuddle kiss and light off.
Before the TV good night song, there should be a process as well. Eat at the same time, Bath and pajamas on....or what ever.
Keep to the same process and don't vary from that. The process should be predictable for the child so they know what's next.
A child who is unsettled could be feeling unsure and be wanting reassurance. They are not sleeping solidly at night so could be waking up partly tired. Tired children tend to be more irritable and less patient, which doesn't help your situation.
A patient child might listen a bit more when you explain something.
Also, if you allow the child to eat sweets or chocolate in the afternoon and evening, the sugar gives the child a bit more energy which they might be better off having in the morning (if at all). If the child wants a drink (bad habit), give the child water or a sip of water.