Hi - yes, we are in the same boat with DD, 8. She has had periods of daily poo accidents ever since a bad bout of constipation at about age 4. It comes and goes, but lockdown has brought it on again.
There is lots of advice on the Eric site www.eric.org.uk/
Their message seems to be that poo accidents happen because the child's rectal passage is stretched out, because of hard faecal matter that's stuck in there, so some poo leaks out without the child noticing. Or, when they need to go, they don't get 'the feeling' because their muscles down there aren't right.
Unfortunately I don't have a good solution. My DD has seen two GPs and a paediatrician, and they all prescribed laxatives, which just cause more accidents and don't work in the long term. Movicol (stool softener) is useless and it's hard work to make them drink it. Dulcolax, a bowel stimulant, was better. You give it to them the night before and then (hopefully) they go in the morning, then it's done for the day.
You could ask your GP, since the problem is just as likely to be physical as psychological. In the meantime, I'd recommend giving your DS a good breakfast with fruit and LOTS of water/juice, and prunes if he'll take them, then getting him to sit on the toilet every day for a good while (15minutes) after breakfast, to try to train his body to go then.
Good luck - I feel for you - it's a nasty problem...