All of mine went though that around the 4-6 months mark. Good sleepers and it’s a shock when it happens and feels like it lasts forever! I vaguely remember it being something to do with their growth, they will have different development points that effect their normal.

It could be teething. Of a day he’s busy with other things taking his mind off the pain. At night, if it hurts he’ll notice it more because it’s more noticeable

If you baby is suddenly growing quickly it can result in more hunger and feeds needed.
There may also be more teeth coming that you can’t see clear evidence of yet.
Sometimes the gum can go back up the side of a tooth that has already come through

That’s pretty normal from memory I believe. They have some mental development changes happening around there and teething will disturb their sleep, even if they don’t seem too bothered by it. I would recommend downloading “The Wonder Weeks” app if you haven’t already. It has helped me to understand my kids weirdness a lot!

May be he scared during his sleep may be any dream it may because of teething as well

Most likely more teeth!