Baby not interested in sitting or tummy time

My little man will be 4 months old on Dec. 12. He HATES tummy time... will almost immediately roll over onto his back every time. He also has zero interest in sitting up. He doesn’t even try to support himself with his arms. The only time he’s happy is when he’s standing. He’ll stand until those little legs can’t stand anymore. Tips?

It’s hard because our first son was sitting on his own at 4 months and this time around, we have a kid who just screams if he’s put on tummy time and will face plant or throw himself backwards when we set him up to sit.