I linked in the settling in guides in your other post but here they are again
New Owners' Most Helpful How-To Guides and Information.
as you only got him in the last day or so, it’s going to take a while for him to settle in and bond with you.
Regarding the behaviours between the both of them, it all sounds entirely normal. You don’t need to do anything. As they are within the two weeks introduction period, you are going to see a lot of dominance behaviours.
Again, as a new piggy, he is still settling in. He will most likely be eating hay when you aren’t looking. Ensure you have plenty of hay everywhere around the cage and in hideys so he doesn’t have to come out if he doesn’t want to.
As long as he is eating enough hay to enable him to gain weight - again, lifelong weekly weighing is essential