Regulation is key.
It can be hugely difficult for an autistic child to switch back into school mode once they have arrived home. At school they are likely working very hard to cope with the demands, and once they get home they may need to decompress. Bottle of fizzy pop analogy. Homework can be a demand to switch back into school mode, when they are in their safe, non-school space.
Things that helped us:
Getting some of the homework done in the lesson it is set. If the dc had finished the classwork, they would start on the homework.
Staying on at school for Homework Club. This needed careful navigating, as the dc needed to understand how it worked and how to ask for help from the supervising adult. Also a plan for which topic they would work on each day.
Doing homework the moment they walked in. Their snack would be ready set out for them on the kitchen table, they would walk in, brief “Hello”, straight to the table, books/laptop out, work. No distraction. Books closed after X set time, no mention of work unless they wanted to discuss it. Decompression time.
Alternatively, decompression time straight away. The trampoline was brilliant for this, also swings. Snack at some point during decompression. Then homework, again in a communal part of the house.
All these strategies needed to be discussed and agreed with the dc. Clear timings. Some worked better for one child than for another. Some worked better for one subject than for another. We needed that weird balance of flexibility and consistency that is part of living with autism.